TY - JOUR A1 - Sachse, René A1 - Hodoroaba, Vasile-Dan A1 - Hertwig, Andreas A1 - Kotil, L. A1 - Kraehnert, R. T1 - Analysis of elemental composition and porosity of mesoporous iridium titanium mixed oxide thin films for energy application by SEM/EDS N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with energy dispersive X-ray spectroscopy (EDS) at an SEM. KW - Electron probe microanalysis (EPMA) KW - Iridium-titanium mixed oxides KW - Spectroscopic ellipsometry KW - Mesoporous thin films KW - NanoSIMS PY - 2019 DO - https://doi.org/10.1017/S1431927619009589 SN - 1431-9276 (Print) SN - 1435-8115 (Online) VL - 25 IS - S2 (August) SP - 1770 EP - 1771 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-48768 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sachse, René A1 - Hertwig, Andreas A1 - Kraehnert, R. A1 - Hodoroaba, Vasile-Dan T1 - Analysis of mesoporous iridium oxide thin films by the combined methodical approach SEM/EDS/STRATAGem N2 - For the determination of porosity of Ir oxide thin films, electron probe microanalysis (EPMA) can be used as part of a combined SEM/EDS/STRATAGem analysis. The mass deposition (in μg cm-2) of films was calculated with the analysis software STRATAGem via k-values measured with EDS. The average density of coated films was obtained from the mass deposition and the film thickness as measured by the cross-section SEM. The porosity was calculated by dividing the average film density by the bulk (theoretical) density of the film material. Film porosities were counterchecked by spectroscopic ellipsometry (SE) using the Bruggeman effective medium approximation (BEMA). The results obtained by both analytical approaches/methods used, SEM/EDS/STRATAGem and SE were in good agreement. KW - Porous thin films KW - Iridium oxide KW - Electron probe microanalysis (EPMA) KW - Spectroscopic ellipsometry PY - 2018 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/analysis-of-mesoporous-iridium-oxide-thin-films-by-the-combined-methodical-approach-semedsstratagem/7607018338B542D8B8C4D944392781EF DO - https://doi.org/10.1017/S1431927618004300 SN - 1431-9276 SN - 1435-8115 VL - 24 IS - S1 (August) SP - 762 EP - 763 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-45951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sachse, René A1 - Bernsmeier, D. A1 - Schmack, R. A1 - Häusler, I. A1 - Hertwig, Andreas A1 - Kraffert, K. A1 - Nissen, J. A1 - Kraehnert, R. T1 - Colloidal bimetallic platinum–ruthenium nanoparticles in ordered mesoporous carbon films as highly active electrocatalysts for the hydrogen evolution reaction N2 - Hydrogen features a very high specific energy density and is therefore a promising candidate for clean fuel from renewable resources. Water electrolysis can convert electrical energy into storable and transportable hydrogen gas. Under acidic conditions, platinum is the most active and stable monometallic catalyst for the hydrogen evolution reaction (HER). Yet, platinum is rare and needs to be used efficiently. Here, we report a synthesis concept for colloidal bimetallic platinum–ruthenium and rhodium–ruthenium nanoparticles (PtRuNP, RhRuNP) and their incorporation into ordered mesoporous carbon (OMC) films. The films exhibit high surface area, good electrical conductivity and well-dispersed nanoparticles inside the mesopores. The nanoparticles retain their size, crystallinity and composition during carbonization. In the hydrogen evolution reaction (HER), PtRuNP/OMC catalyst films show up to five times higher activity per Pt than Pt/C/Nafion® and PtRu/C/Nafion® reference catalysts. KW - Ordered mesoporous carbon KW - Bimetallic noble metal nanoparticles KW - Platinum-ruthenium colloid KW - Electrolysis KW - Hydrogen evolution reaction PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506868 DO - https://doi.org/10.1039/C9CY02285F SN - 2044-4753 VL - 10 IS - 7 SP - 2057 EP - 2068 PB - Royal Society of Chemistry AN - OPUS4-50686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Bernsmeier, Denis A1 - Hertwig, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Kraehnert, Ralph T1 - Spectroscopic ellipsometry for the determination of thickness and porosity of mesoporous metal oxide films N2 - Thin mesoporous metal oxide films are versatile and attractive candidates for several energy applications like photovoltaics, electrolysis or batteries. Due to their high surface area and ordered pore structure, mesoporous metal oxides demonstrate higher activities. The performance of the porous films is affected by properties like size and shape of the mesopores as well as the crystallinity of the framework. The exact determination and metrological evaluation of the complex morphology of thin mesoporous films requires a new analytical approach employing to combined data of different analytical methods. In this contribution we present a novel evaluation procedure for spectroscopic ellipsometry (SE) to analyse thin mesoporous iridium oxide films. Mesoporous iridium oxide films were prepared via dip-coating of a solution containing a triblock-copolymer as structure directing agent and an iridium precursor in ethanol. Deposited films were calcined in air at temperatures between 300 and 600 °C. Their morphology was studied with SEM and an electron probe microanalysis (EPMA) and correlated via SE with a Bruggeman effective medium approximation (BEMA). The developed SE model described the film thickness as well as the porosity. ... The contribution will assess in detail the novel approach to analyse the morphology and porosity of thin metal oxide films with spectroscopic ellipsometry. Moreover, the advantages of the new developed approach will be discussed as well as combination of datasets from multiple measurements to development new methods for innovative energy technologies. T2 - 30. Deutsche Zeolith-Tagung gemeinsam mit dem Jahrestreffen der ProcessNet-Fachgruppe Adsorption CY - Christian-Albrechts-Universität zu Kiel, Germany DA - 28.02.2018 KW - Mesoporous materials KW - Iridium oxide films KW - Electro catalyst KW - Spectroscopic ellipsometry KW - Thin film metrology KW - Multi-sample analysis PY - 2018 AN - OPUS4-45134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Hertwig, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Kraehnert, R. T1 - Spectroscopic ellipsometry for the determination of thickness and porosity of mesoporous metal oxide films N2 - Thin mesoporous metal oxide films are versatile and attractive candidates for several energy applications like photovoltaics, electrolysis or batteries. Due to their high surface area and ordered pore structure, mesoporous metal oxides demonstrate higher activities. The performance of the porous films is affected by properties like size and shape of the mesopores as well as the crystallinity of the framework. The exact determination and metrological evaluation of the complex morphology of thin mesoporous films requires a new analytical approach employing to combined data of different analytical methods. In this contribution we present a novel evaluation procedure for spectroscopic ellipsometry (SE) to analyse thin mesoporous iridium oxide films. Mesoporous iridium oxide films were prepared via dip-coating of a solution containing a triblock-copolymer as structure directing agent and an Iridium precursor in ethanol. Deposited films were calcined in air at temperatures between 300 and 600 °C. Their morphology was studied with SEM and an electron probe microanalysis (EPMA) and correlated via SE with a Bruggeman effective medium approximation (BEMA). The developed SE model described the film thickness as well as the porosity. ... The contribution will assess in detail the novel approach to analyse the morphology and porosity of thin metal oxide films with spectroscopic ellipsometry. Moreover, the advantages of the new developed approach will be discussed as well as combination of datasets from multiple measurements to development new methods for innovative energy technologies. T2 - 10th Workshop Ellipsometry 2018 CY - Chemnitz University of Technology, Germany DA - 19.03.2018 KW - Mesoporous materials KW - Iridium oxide films KW - Electro catalyst KW - Spectroscopic ellipsometry KW - Thin film metrology KW - Multi-sample analysis PY - 2018 AN - OPUS4-45143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Bernsmeier, D. A1 - Hertwig, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Kraehnert, R. T1 - Spectroscopic ellipsometry for the determination of thickness and porosity of mesoporous metal oxide films N2 - Thin mesoporous metal oxide films are versatile and attractive candidates for several energy applications like photovoltaics, electrolysis or batteries. Due to their high surface area and ordered pore structure, mesoporous metal oxides demonstrate higher activities. The performance of the porous films is affected by properties like size and shape of the mesopores as well as the crystallinity of the framework. The exact determination and metrological evaluation of the complex morphology of thin mesoporous films requires a new analytical approach employing to combined data of different analytical methods. In this contribution we present a novel evaluation procedure for spectroscopic ellipsometry (SE) to analyse thin mesoporous iridium oxide films. Mesoporous iridium oxide films were prepared via dip-coating of a solution containing a triblock-copolymer as structure directing agent and an iridium precursor in ethanol. Deposited films were calcined in air at temperatures between 300 and 600 °C. Their morphology was studied with SEM and an electron probe microanalysis (EPMA)and correlated via SE with a Bruggeman effective medium approximation (BEMA). The developed SE model described the film thickness as well as the porosity. Figure 1a shows a top-view SEM image of mesoporous IrO2 film calcined at 375 °C. The image reveals that the films exhibit a well-ordered mesopore structure with an average pore diameter of 16 nm and a periodic distance between pore centres of 24 nm (FFT inset). Figure 1b is a parity plot of film thicknesses determined by cross-section SEM versus SE of IrO2 film samples prepared at different calcination temperatures. The porosity from the SE model is in good agreement to the porosity values obtained by EPMA. The contribution will assess in detail the novel approach to analyse the morphology and porosity of thin metal oxide films with spectroscopic ellipsometry. Moreover, the advantages of the new developed approach will be discussed as well as combination of datasets from multiple measurements to development new methods for innovative energy technologies. T2 - 30. Deutsche Zeolith-Tagung und Jahrestreffen der ProcessNet-Fachgruppe Adsorption CY - Kiel, Germany DA - 28.02.2018 KW - Mesoporous materials KW - Iridium oxide films KW - Electro catalyst KW - Spectroscopic ellipsometry KW - Thin film metrology KW - Multi-sample analysis PY - 2018 AN - OPUS4-45101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René T1 - Towards hydrogen economy: correlative ex-situ ellipsometric analysis and operando investigation during oxygen evolution reaction of mesoporous iridium oxides films N2 - In the face of rising energy demand and the impending climate change the development of a sustainable, fossil-free fuel and chemical production is of global importance. One possible goal is the development of electrochemical conversion processes using catalysts. Porous materials play an important role in such energy applications. The key to the development of improved catalysts is a better understanding of the relations between their performance, stability and physico-chemical properties. However, the complex morphology of such catalysts constitutes a challenge even for modern analytical techniques. Spectroscopic ellipsometry (SE) is a versatile method for studying material properties by using appropriate models (e.g. film thickness, optical and electronic properties). The fact that the material properties cannot be taken directly from the measured spectra, the developed models have to be validated. In a first step, the model for the ellipsometric fit studies of a calcination series of mesoporous iridium oxide films (300 – 600 °C) was investigated and validated with respect to their material properties. Moreover, the electronic structures of the catalysts reveal a direct correlation with electrochemical activities. The development of an environmental cell offers the possibility of investigations under real conditions. This will allow changes in the optical and electronic properties during the electrocatalytic oxygen evolution reaction. T2 - Colloquium Department Seminar 6. CY - BAM, Berlin, Germany DA - 03.03.2020 KW - Hydrogen economy KW - Correlative ex-situ ellipsometric analysis KW - Ellipsometric operando investigation KW - Oxygen evolution reaction KW - Mesoporous iridium oxides films PY - 2020 AN - OPUS4-51215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Hodoroaba, Vasile-Dan A1 - Hertwig, Andreas A1 - Matjacic, L. A1 - McMahon, G. A1 - Kotil, L. A1 - Bernsmeier, D. A1 - Kraehnert, R. T1 - Analysis of elemental composition and porosity of mesoporous iridium titanium mixed oxide thin films for energy application by SEM/EDS N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with energy dispersive X-ray spectroscopy (EDS) at an SEM. T2 - Microscopy & Microanalysis 2019 Meeting CY - Portland, OR, USA DA - 04.08.2019 KW - Mesoporous mixed metal oxide films KW - SEM/EDS/STRATAGem KW - EPMA KW - Ellipsometry KW - NanoSIMS PY - 2019 AN - OPUS4-48767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Hertwig, Andreas A1 - Kraehnert, R. A1 - Hodoroaba, Vasile-Dan T1 - Analysis of elemental composition and porosity of mesoporous IrOx-TiOx thin films by SEM/EDS N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by Electron Probe Microanalysis (EPMA) with energy dispersive X-ray spectroscopy (EDS) at an SEM. T2 - EMAS 2019 - 16th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS CY - Trondheim, Norway DA - 19.05.2019 KW - Electron probe microanalysis (EPMA) KW - Iridium-titanium mixed oxides KW - Spectroscopic ellipsometry KW - Mesoporous thin films PY - 2019 AN - OPUS4-48769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Kotil, L. A1 - Hodoroaba, Vasile-Dan A1 - Bernsmeier, Denis A1 - Kraehnert, R. A1 - Hertwig, Andreas T1 - Spectroscopic ellipsometric analysis of elemental composition and porosity of mesoporous iridium-titanium mixed oxide thin films for electrocatalytic splitting of water N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge for modern analytical techniques and requires approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by spectroscopic ellipsometry (SE). Mesoporous iridium oxide - titanium oxide (IrOx-TiOx) films were prepared via dip-coating of a solution containing a triblock-copolymer as structure-directing agent, an iridium precursor as well as a titanium precursor in ethanol. Deposited films with different amounts of iridium (0 wt%Ir to 100 wt%Ir) were synthesized and calcined in air. The thin films were analyzed with SE using the Bruggeman effective medium approximation (BEMA) for modelling. The results were compared with electron probe microanalysis (EPMA) as part of a combined SEM/EDS/STRATAGem Analysis. T2 - 8th International conference on spectroscopic ellipsometry (ICSE-8) CY - Barcelona, Spain DA - 26.05.2019 KW - Mesoporous iridium-titanium mixed oxides KW - Thin films KW - Spectroscopic ellipsometry KW - Oxygen evolution reaction KW - EPMA KW - Ellipsometric porosimetry PY - 2019 AN - OPUS4-48387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Pflüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Hertwig, Andreas A1 - Kraehnert, Ralph T1 - Operando electrochemical spectroscopic ellipsometry: Material properties of highly active mesoporous IrO IrOxfilms revealed under realistic OER conditions N2 - Rising energy demand and the impending climate change require the development of a sustainable, fossil-free fuel and chemical production on a global scale. Hydrogen production via water electrolysis will be a fundamental cornerstone in this endeavor. The activity and stability of respective electrode coatings strongly depends on the coating's properties, i.e. phase composition, crystallinity, electrical conductivity, accessible surface, wettability and many other factors. The key to the development of improved catalysts is a better understanding of the relations between their performance, stability and physicochemical properties. However, those relations can be complex, and are strongly influenced also by the reaction environment. Hence, operando analysis of the catalyst material during catalysis at realistic potentials and current densities is highly desirable. Yet, many analytical techniques cannot be applied in liquid environments at realistic potentials and current densities. We propose environmental ellipsometric analysis in a dedicated electrochemical flow cell as a new method to evaluate gas evolution reactions operando under realistic working conditions. Figure 1 illustrates schematically the developed technique. Key factors to success are highly active model-type catalysts with template-controlled porosity, a suitable sample environment, a deep understanding of the spectroscopic method and respective model development, as well as concise cross validation with numerous other analytical techniques. The method was developed and validated by analyzing a calcination series (300 - 600°C) of mesoporous templated IrOx films ex-situ and operando under oxygen evolution reaction (OER) conditions. The employed environmental electrochemical spectroscopic ellipsometric analysis (ECSE) revealed during OER the change of optical and electronic properties, i.e. the dielectric functions (real ε1 and imaginary part ε2), electrical and electronic properties such as resistivity (ρ) and band-to-band transitions (p-d band transitions). Film thickness and porosity were validated by means of scanning electron microscopy (SEM), X-ray reflectometry (XRR) or ellipsometric porosimetry (EP), electrical and electronic properties by means of conductivity measurements, X-ray photoelectron spectroscopy (XPS) or UV-Vis-NIR absorption spectroscopy. The electronic structures of the catalysts from valence electron energy loss spectra (VEELS) derived from the real (ε1) and imaginary part (ε2) of the dielectric function from SE measurements reveal a direct correlation with electrochemical activities in OER. In the presentation reversible and irreversible potential-dependent changes of the catalyst properties during operation will be discussed along with the dynamics of gas formation, transport and dissolution at different potentials. T2 - 54. Jahrestreffen deutscher Katalytiker CY - Online meeting DA - 16.03.2021 KW - Spectroscopic ellipsometry KW - Electrocatalysis KW - Oxygen evolution reaction KW - Mesoporous iridium oxide films KW - Non-destructive operando analysis PY - 2021 AN - OPUS4-52928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Pflüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Hertwig, Andreas A1 - Kraehnert, Ralph T1 - Operando electrochemical spectroscopic ellipsometry: Material properties of highly active mesoporous IrO IrOxfilms revealed under realistic OER conditions N2 - Rising energy demand and the impending climate change require the development of a sustainable, fossil-free fuel and chemical production on a global scale. Hydrogen production via water electrolysis will be a fundamental cornerstone in this endeavor. The activity and stability of respective electrode coatings strongly depends on the coating's properties, i.e. phase composition, crystallinity, electrical conductivity, accessible surface, wettability and many other factors. The key to the development of improved catalysts is a better understanding of the relations between their performance, stability and physicochemical properties. However, those relations can be complex, and are strongly influenced also by the reaction environment. Hence, operando analysis of the catalyst material during catalysis at realistic potentials and current densities is highly desirable. Yet, many analytical techniques cannot be applied in liquid environments at realistic potentials and current densities. We propose environmental ellipsometric analysis in a dedicated electrochemical flow cell as a new method to evaluate gas evolution reactions operando under realistic working conditions. Figure 1 illustrates schematically the developed technique. Key factors to success are highly active model-type catalysts with template-controlled porosity, a suitable sample environment, a deep understanding of the spectroscopic method and respective model development, as well as concise cross validation with numerous other analytical techniques. The method was developed and validated by analyzing a calcination series (300 - 600°C) of mesoporous templated IrOx films ex-situ and operando under oxygen evolution reaction (OER) conditions. The employed environmental electrochemical spectroscopic ellipsometric analysis (ECSE) revealed during OER the change of optical and electronic properties, i.e. the dielectric functions (real ε1 and imaginary part ε2), electrical and electronic properties such as resistivity (ρ) and band-to-band transitions (p-d band transitions). Film thickness and porosity were validated by means of scanning electron microscopy (SEM), X-ray reflectometry (XRR) or ellipsometric porosimetry (EP), electrical and electronic properties by means of conductivity measurements, X-ray photoelectron spectroscopy (XPS) or UV-Vis-NIR absorption spectroscopy. The electronic structures of the catalysts from valence electron energy loss spectra (VEELS) derived from the real (ε1) and imaginary part (ε2) of the dielectric function from SE measurements reveal a direct correlation with electrochemical activities in OER. In the presentation reversible and irreversible potential-dependent changes of the catalyst properties during operation will be discussed along with the dynamics of gas formation, transport and dissolution T2 - E MRS 2021 SPRING MEETING CY - Online meeting DA - 31.05.2021 KW - Spectroscopic ellipsometry KW - Ectrocatalysis KW - Oxygen evolution reaction KW - Mesoporous iridium oxide films KW - Non-destructive operando analysis PY - 2021 AN - OPUS4-52929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sachse, René A1 - Pflüger, Mika A1 - Velasco-Vélez, Juan-Jesús A1 - Sahre, Mario A1 - Radnik, Jörg A1 - Bernicke, Michael A1 - Bernsmeier, Denis A1 - Hodoroaba, Vasile-Dan A1 - Krumrey, Michael A1 - Strasser, Peter A1 - Kraehnert, Ralph A1 - Hertwig, Andreas T1 - Operando electrochemical spectroscopic ellipsometry: Material properties of highly active mesoporous IrOx films revealed under realistic OER conditions N2 - Hydrogen production via water electrolysis will be an essential cornerstone in development of sustainable, fossil-free fuel and chemical production on a global scale. The activity and stability of each catalyst is highly dependent on the properties of the coating, i.e., phase composition, crystallinity, accessible surface area, and many other factors. The key to developing improved catalysts is a better understanding of the relationships between their performance, stability, and physicochemical properties. However, these relationships can be complex and are also strongly influenced by the reaction environment. Therefore, operando analysis of the catalyst material during catalysis at realistic potentials and current densities is highly desirable. However, many analytical techniques cannot be applied in liquid environments at realistic potentials and current densities. We propose environmental ellipsometric analysis in a dedicated electrochemical flow cell as a method to evaluate gas evolution reactions operando under realistic working conditions. Figure 1 illustrates schematically the developed technique. Key factors to success are highly active model-type catalysts, a suitable sample environment, and a deep understanding of the appropriate model development, as well as concise cross validation with numerous other analytical techniques. The method was developed and validated by analyzing a calcination series (300 – 600 °C) of mesoporous templated IrOx films ex-situ and operando under oxygen evolution reaction (OER) conditions. The employed environmental electrochemical spectroscopic ellipsometric (ECSE) analysis revealed during OER the change of optical and electronic properties, i.e. the dielectric functions, resistivity and band-to-band transitions (p-d band transitions). Film thickness and porosity were validated by means of scanning electron microscopy (SEM), X-ray reflectometry (XRR) or ellipsometric porosimetry (EP), electrical and electronic properties by means of conductivity measurements, X-ray photoelectron spectroscopy (XPS) or UV-Vis-NIR absorption spectroscopy. The electronic structures of the catalysts from valence electron energy loss spectra (VEELS) derived from ε1 and ε2 from SE measurements reveal a direct correlation with electrochemical activities in OER. In the presentation reversible and irreversible potential-dependent changes of the catalyst properties during operation will be discussed along with the dynamics of gas formation, transport and dissolution at different potentials. T2 - 11th Workshop Ellipsometry (WSE 11) CY - Steyr, Austria DA - 06.09.2021 KW - Ectrocatalysis KW - Mesoporous iridium oxide films KW - Non-destructive operando analysis KW - Oxygen evolution reaction KW - Spectroscopic ellipsometry PY - 2021 AN - OPUS4-53915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rietz, U. A1 - Küchler, S. A1 - Lerche, D. A1 - Lange, Thorid A1 - Hielscher, Stefan A1 - Beck, Uwe T1 - Zentrifugalkraftbasierte Mehrprobenprüfung in einer analytischen Zentrifuge zur Bestimmung von Kleb- und Haftfestigkeiten: Metallische Referenzverbunde, Plasmaaktivierung von Polymeren, Schichthaftung auf GFK, Wirkung von Primern N2 - Das Fügeverfahren Kleben bietet viele Vorteile wie z.B. das Verbinden schwieriger Materialklassen, geringe thermische Belastung (Strukturveränderung/-schwächung) der Fügepartner und eine Lastverteilung über den gesamten Fügebereich. Die Auswahl an verfügbaren Klebstoffen und Vorbehandlungsoptionen ist dabei ebenfalls vielfältig. Einige Polymere weisen darüber hinaus Eigenschaften auf, die eine Herstellung von festen und dauerhaft beanspruchbaren Klebverbindungen erschweren. Mittels Oberflächenbehandlung, z.B. durch Plasmafeinreinigung bzw. –aktivierung, können die Grenzflächern solcher Polymere - bezogen auf die Eignung als Fügeteilpartner – optimiert werden. Schnelle Prüfverfahren zur Ermittlung von Verbundeigenschaften sind somit erforderlich. Das Messprinzip Centrifugal Adhesion Testing Technologie verwendet die radial gerichtete Zentrifugalkraft als Belastungsgröße des zu testenden Verbunds, die durch Variation der Drehzahl gesteuert wird. Bei Erreichen der kritischen Beanspruchung trennt sich ein aufgeklebter Prüfstempel vom Substrat. Zeitgleich wird ein positionsbezogenes IR-Signal aus dem drehenden Rotor an das Basisgerät gesendet und zusammen mit der Drehzahl an die PC-Software übertragen. Für jede Probe wird die Bruchkraft berechnet und in Echtzeit angezeigt. Der Adhesion Analyser LUMiFrac® untersucht bis zu acht Prüfkörper unter identischen Bedingungen. Das neue Messprinzip erfüllt die Anforderungen von DIN EN 15870, DIN EN 14869-2, ISO 4624 sowie DIN EN 13144. Die Multiprobentestung ermöglicht schnelle Charakterisierungen von Klebverbindungen. So kann der Effekt einer Plasmabehandlung von Bauteilen auf die Verbundfestigkeit zeitsparend bestimmt werden. Die gezielte Veränderung unterschiedlicher Plasma-Parameter, wie beispielsweise, die Plasmazusammensetzung, der Abstand vom Plasmabrenner zur Oberfläche oder die Verweildauer unter dem Brenner, beeinflußt die Festigkeit des Klebsystems und ist dem LUMiFrac direkt quantifizierbar. Neben der Festigkeitsbestimmung von Klebverbindungen ist die Haftung von Schichtsystemen ein wichtiger Anwendungsbereich. Ergebnisse für Zug- und Scherbeanspruchung, realisiert mit unterschiedlichen Prüfkörper-Geometrien, werden vorgestellt. Ferner werden verschiedene festigkeitsbeeinflussende Faktoren, wie Prüfgeschwindigkeit oder Substratverformung bei Beanspruchung untersucht T2 - 35. Workshop des ak-adp CY - Nuremberg, Germany DA - 20.11.2019 KW - Adhäsion KW - Mehrprobenprüfung KW - Analytische Zentrifuge KW - Kleb- und Haftfestigkeit PY - 2019 SN - 978-3-00-063646-2 SP - 100 EP - 109 AN - OPUS4-50149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rietz, U. A1 - Lerche, D. A1 - Hielscher, Stefan A1 - Grunwald, Daniel A1 - Beck, Uwe T1 - Determination of coating properties by using analytical centrifugation N2 - The majority of all products have coated surfaces designed to fulfil different requirements. Building constructions are exposed to external influences like a wide temperature and humidity range, rain and UV radiation to name a few. The extension of machine life for metal cutting tools, like drills or milling cutters is another field of application for coated surfaces. The surfaces have to be modified in a way to maintain their specific functionality. Although adhesion testing of coatings is of great interest, it is still a challenge to obtain reliable quantitative results and to meet economic requirements. In this talk we deal with the curing behaviour of different 2-component epoxy paint systems for corrosion protection of metal constructions. After preparation of specimens the strength was determined in specified time intervals during curing. It could be shown that epoxy paints differ significantly on curing time as well as final strength. The second experimental study deals with coating systems on glass fibre reinforced plastics which are used for wind power turbines to reduce abrasive wear and ice adhesion for aerodynamic and safety reasons. All measurements have been carried out by CAT-TechnologyTM (Centrifugal Adhesion Testing), which uses the radially directed centrifugal force as test-load. The multi-sample test instrument analyses up to eight test specimen under identical testing conditions. By varying the rotational speed (100 rpm up to 13,000 rpm), forces from 0.1 N to 6.5 kN are applied. Upon reaching the critical rupture force, the stamp separates from the substrate and a sample related IR-signal is sent from the spinning rotor. For each test specimen breaking force is calculated and displayed in real-time. The innovative measurement principle meets the requirements of DIN EN 15870 and ISO 4624. T2 - EURADH 2018 CY - Lisbon, Portugal DA - 05.07.2018 KW - Adhesive strength determination KW - CAT-technology KW - Centrifugal adhesion testing KW - Metal coatings KW - Decorative coatings on polymer substrates PY - 2018 AN - OPUS4-46001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reetz, U. A1 - Lerche, D. A1 - Hielscher-Hofinger, Stefan A1 - Kubitzki, Jan A1 - Beck, Uwe T1 - Load- and path-controlled determination of bonding strength of butt joints - Comparison between tensile testing machine and centrifuge technology N2 - The round robin test proves that the CAT-Technology provides statistically indistinguishable test results compared to TTM. A supplement to DIN EN 15870 taking into account CAT-Technology (with reference to equivalent increases of load and displacement) as second normative test method appears to make sense. A presentation of a revision proposal at CEN TC 193 has been introduced with the decision to conduct a survey using the unchanged German revision proposal. T2 - EURADH 2021 - 13 th European Adhesion Conference CY - Online meeting DA - 11.10.2021 KW - CAT – Technology KW - Tensile testing machine (TTM) KW - Round robin test KW - Validation PY - 2021 AN - OPUS4-53948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reetz, U. A1 - Beck, Uwe A1 - Hielscher-Hofinger, Stefan A1 - Lerche, D. T1 - CAT -Technologie (CentrifugalAdhesionTesting) im Standardisierungsprozess N2 - Der DIN Ringversuch weist nach, dass die CAT Technologie zur ZPM Prüfung statistisch nicht unterscheidbare Prüfergebnisse liefert, so dass lediglich eine Ergänzung der DIN EN 15870 unter Berücksichtigung der CAT-Technologie (mit Bezug auf äquivalente Kraft und Weg zunahmen) als zweiter normativer Prüfmethode sinnvoll erscheint. Vorstellung des Revisionsvorschlages im CEN TC 193 am 08.04.2021 mit dem Beschluss, eine Umfrage unter Verwendung des unveränderten deutschen Revisionsvorschlages durchzuführen. T2 - SKZ-Expertenkreis „Kleben und Oberflächentechnik für Kunststoffe“ 2021 CY - Online meeting DA - 22.09.2021 KW - Centrifugal Adhesion Testing (CAT) KW - Zweistichproben t Test: (ZPM) KW - Ringversuch KW - Validierung KW - DIN EN 15870 PY - 2021 AN - OPUS4-53964 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Netzband, Olivia A1 - Lagleder, Michaela A1 - Beck, Uwe T1 - Materialographische Untersuchungen an Funktionsschichten N2 - Oberflächenmodifizierte Grundwerkstoffe, insbesondere solche mit funktionellen Schichten, sind in unterschiedlichsten Branchen und Anwendungen anzutreffen. Es werden Quer- und Kalottenschliffe von Einfach- und Mehrschichtsystemen mit Beispielen aus dem Bereich des Korrosions- und Verschleißschutzes sowie dekorativer Anwendungen auf unterschiedlichsten Grundwerkstoffen (X5CrNi1810 Stahl, 100Cr6 Stahl, Hartmetall, ABS und Pappe) vorgestellt. Ebenso vielfältig wie die Grundwerkstoffe sind die Oberflächenmodifizierungen mit Funktionsschichten auf Basis von Nitrierungen, Hartstoffen, diamantähnlichem Kohlenstoff, Metallisierungen und Lackschichten mit Interferenzpigmenten. Neben der Identifikation von Schichtdefekten gilt das Hauptaugenmerk der materialographischen Analyse der Erfüllung der Schichtdickenspezifikation und der Bewertung der Homogenität der Schichtdicke auch bei kritischen Geometrien. Zur Validierung der Schichtdicken- bzw. Längenbestimmung im Querschliff wurde ein Laborvergleichsversuch mit einem Nickel-beschichteten Kupferdraht durchgeführt, den alle der 10 Teilnehmer bestanden. T2 - 55. Materialographie-Tagung CY - Online meeting DA - 29.09.2021 KW - Metallographie KW - Schichtdicken KW - Korrosion KW - Kalottenverfahren PY - 2021 AN - OPUS4-53504 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Basedau, Frank A1 - Hofman, Detlef A1 - Beck, Uwe T1 - Fiber Bragg Gratings for In-Situ Stress Monitoring of Electrochemical Deposition N2 - The in-situ monitoring of electrochemical deposition (ECD) processes is still a challenge regarding the measurement of the effective temperature of the substrate and the formation of mechanical stress in the layer under given plating conditions. Monitoring problems can be solved by applying a pre-coated fiber Bragg grating (FBG) to the electrolytic process as the shift of the Bragg wavelength is affected by both the temperature of the electrolyte near the substrate and the stress formation in the growing layer. The experimental FBG set-up and the quantitative determination of temperature- and stress-related strain is described for a nickel-iron electrolyte. KW - Fiber Bragg grating (FBG) KW - Electrochemical deposition (ECD) KW - Optical fibers PY - 2019 DO - https://doi.org/10.1149/2.0111906jes SN - 0013-4651 VL - 166 IS - 6 SP - B312 EP - B315 PB - Electrochemical Society CY - Pennington, NJ AN - OPUS4-47738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mirabella, Francesca A1 - Mezera, Marek A1 - Wasmuth, Karsten A1 - Hertwig, Andreas A1 - Richter, Anja A1 - Schwibbert, Karin A1 - Krüger, Jörg A1 - Bonse, Jörn A1 - Hodoroaba, Vasile-Dan T1 - ToF-SIMS as a new tool for nano-scale investigation of ps-laser-generated surface structures on titanium substrates N2 - In recent years, the fabrication of laser-generated surface structures on metals such as titanium surfaces have gained remarkable interests, being technologically relevant for applications in optics, medicine, fluid transport, tribology, and wetting of surfaces. The morphology of these structures, and so their chemistry, is influenced by the different laser processing parameters such as the laser fluence, wavelength, pulse repetition rate, laser light polarization type and direction, angle of incidence, and the effective number of laser pulses per beam spot area. However, the characterization of the different surface structures can be difficult because of constraints regarding the analytical information from both depth and the topographic artifacts which may limit the lateral and depth resolution of elemental distributions as well as their proper quantification. A promising technique to investigate these structures even at the nano-scale is Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), a very surface sensitive technique that at the same time allows to perform depth-profiling, imaging and 3D-reconstruction of selected ion-sputter fragment distributions on the surface. In this study we combine chemical analyses such as Energy Dispersive X-ray spectroscopy (EDX) and high-resolution scanning electron microscopy (SEM) analyses with ToF-SIMS to fully characterize the evolution of various types of laser-generated micro- and nanostructures formed on Ti and Ti alloys at different laser fluence levels, effective number of pulses and at different pulse repetition rates (1 – 400 kHz), following irradiation by near-infrared ultrashort laser pulses (925 fs, 1030 nm) in air environment or under argon gas flow. We show how this combined surface analytical approach allows to evaluate alteration in the surface chemistry of the laser-generated surface structures depending on the laser processing parameters and the ambient environment. T2 - European Materials Research Society (EMRS) Fall Meeting 2021 CY - Online meeting DA - 20.09.2021 KW - ToF SIMS KW - Nano characterization PY - 2021 AN - OPUS4-53366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mezera, Marek A1 - Alamri, S. A1 - Hendriks, W. A. P. M. A1 - Hertwig, Andreas A1 - Elert, Anna Maria A1 - Bonse, Jörn A1 - Kunze, T. A1 - Lasagni, A. F. A1 - Römer, G. R. B. E. T1 - Hierarchical micro-/nano-structures on polycarbonate via UV pulsed laser processing N2 - Hierarchical micro/-nanostructures were produced on polycarbonate polymer surfaces by employing a two-step UV-laser processing strategy based on the combination of Direct Laser Interference Patterning (DLIP) of gratings and pillars on the microscale (3 ns, 266 nm, 2 kHz) and subsequently superimposing Laser-induced Periodic Surface Structures (LIPSS; 7–10 ps, 350 nm, 100 kHz) which adds nanoscale surface features. Particular emphasis was laid on the influence of the direction of the laser beam polarization on the morphology of resulting hierarchical surfaces. Scanning electron and atomic force microscopy methods were used for the characterization of the hybrid surface structures. Finite-difference time-domain (FDTD) calculations of the laser intensity distribution on the DLIP structures allowed to address the specific polarization dependence of the LIPSS formation observed in the second processing step. Complementary chemical analyzes by micro-Raman spectroscopy and attenuated total reflection Fourier-transform infrared spectroscopy provided in-depth information on the chemical and structural material modifications and material degradation imposed by the laser processing. It was found that when the linear laser polarization was set perpendicular to the DLIP ridges, LIPSS could be formed on top of various DLIP structures. FDTD calculations showed enhanced optical intensity at the topographic maxima, which can explain the dependency of the morphology of LIPSS on the polarization with respect to the orientation of the DLIP structures. It was also found that the degradation of the polymer was enhanced for increasing accumulated fluence levels. KW - Direct laser interference patterning KW - Laser-induced periodic surface structures (LIPSS) KW - Polycarbonate KW - Hierarchical structures KW - Surface functionalization PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509101 DO - https://doi.org/10.3390/nano10061184 SN - 2079-4991 VL - 10(6) IS - Special issue "Laser-generated periodic nanostructures" SP - 1184-1 EP - 1184-19 PB - MDPI CY - Basel AN - OPUS4-50910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Madkour, Sherif A1 - Garwek, Marcel A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Do Interfacial Layers in Thin Films Act as an Independent Layer Within Thin Films? N2 - The thermodynamic behavior of thin PVME films including the irreversible adsorbed layer on the substrate is investigated. In a first step, the growth kinetics of the adsorbed layer was studied combining a leaching technique and atomic force microscopy. Further, it was shown that there is a critical initial film thickness for the formation of a surface-filling adsorbed layer. Additionally, spectroscopic ellipsometry measurements were carried out to investigate the influence of the adsorbed layer on the glass transition temperature of the thin films. For 30 nm films and below, the influence of the adsorbed layer percolates strongly to the bulk-like layer of the film. Finally, the molecular dynamics of the adsorbed layer was studied by broadband dielectric spectroscopy, employing nanostructured-electrode systems. One process was revealed, which was assigned either to molecular fluctuations taking place in a loosely-bounded the part of the adsorbed layer, or to the desorption/adsorption of segments at the substrate. KW - Thin polymer films PY - 2021 DO - https://doi.org/10.1021/acs.macromol.0c02149 VL - 54 IS - 1 SP - 509 EP - 519 PB - ACS Publications AN - OPUS4-52037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Thorid A1 - Hidde, Gundula A1 - Beck, Uwe A1 - Naumann, F. A1 - Kärkkänen, I. A1 - Gargouri, H. T1 - Nanoskalige Haftvermittler zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen N2 - Ziel des Projektes HARFE (Haftfestigkeit Reproduzierbarkeit Festigkeit) war es, eine Er-höhung der Haft- bzw. Klebfestigkeit auf Niedrigenergie-Polymeren (PE, PP, PTFE) zu erreichen. SENTECH realisierte dazu plasmachemische Oberflächenaktivierungen mit O2 und die Abscheidung von Aluminiumoxidschichten (Al2O3) mittels Atomic Layer Deposition (ALD), wobei die Ellipsometrie zum in-situ Monitoring der ALD-Prozesse diente. Die BAM charakterisierte die modifizierten Oberflächen bezüglich der Oberflächenenergie (OFE) und bestimmte die Verbund- bzw. Klebfestigkeit mittels der Zentrifugentechnologie T2 - 14. ThGOT Thementage Grenz- und Oberflächentechnik und 6. Kolloquium Dünne Schichten in der Optik CY - Zeulenroda, Germany DA - 12.03.2019 KW - Haftvermittler KW - ALD-Hybridprozesse KW - Klebfestigkeit KW - Atomic Layer Deposition KW - Al2O3-Schichten KW - Oberflächenenergie PY - 2019 SN - 978-3-00-062102-4 SP - 1 EP - 2 CY - Zeulenroda, Germany AN - OPUS4-47656 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Thorid A1 - Hidde, Gundula A1 - Beck, Uwe A1 - Naumann, F. A1 - Kärkkänen, I. A1 - Gargouri, H. T1 - HARFE: Haftfestigkeit Reproduzierbarkeit Festigkeit „Nanoskalige Haftvermittler zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen“ N2 - Das Poster „HARFE: Haftfestigkeit Reproduzierbarkeit Festigkeit“ widmet sich den nanoskaligen Haftvermittlern zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen. T2 - Netzwerksymposium “Schützen und Veredeln von Oberflächen”, Wildau CY - TH Wildau, Germany DA - 01.03.2018 KW - Verbundfestigkeit KW - Oberflächenenergie KW - ALD-Beschichtung PY - 2018 AN - OPUS4-44399 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, Thorid A1 - Hidde, Gundula A1 - Beck, Uwe A1 - Naumann, F. A1 - Kärkkänen, I. A1 - Gargouri, H. T1 - Nanoskalige Haftvermittler zur Erhöhung der Haft- bzw. Klebfestigkeit unter Verwendung von ALD-Hybridprozessen N2 - Ziel des Projektes HARFE (Haftfestigkeit Reproduzierbarkeit Festigkeit) war es, eine Er-höhung der Haft- bzw. Klebfestigkeit auf Niedrigenergie-Polymeren (PE, PP, PTFE) zu erreichen. SENTECH realisierte dazu plasmachemische Oberflächenaktivierungen mit O2 und die Abscheidung von Aluminiumoxidschichten (Al2O3) mittels Atomic Layer Deposition (ALD), wobei die Ellipsometrie zum in-situ Monitoring der ALD-Prozesse diente. Die BAM charakterisierte die modifizierten Oberflächen bezüglich der Oberflächenenergie (OFE) und bestimmte die Verbund- bzw. Klebfestigkeit mittels der Zentrifugentechnologie T2 - 14. ThGOT Thementage Grenz- und Oberflächentechnik und 6. Kolloquium Dünne Schichten in der Optik CY - Zeulenroda, Germany DA - 12.03.2019 KW - Haftvermittler KW - ALD-Hybridprozesse KW - Klebfestigkeit KW - Atomic Layer Deposition KW - Al2O3-Schichten KW - Oberflächenenergie PY - 2019 AN - OPUS4-47653 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lagleder, Michaela A1 - Netzband, Olivia A1 - Beck, Uwe A1 - Lange, Thorid T1 - Materialographische Untersuchungen an Bauteilen N2 - Eine Grundanforderung an Bauteile ist deren mechanische Integrität, die als Festigkeit (globale Bauteilbeanspruchung) bzw. Tragfestigkeit (lokale Beanspruchung) zu verstehen ist. Die Bauteilfestigkeit wird wesentlich durch das Materialgefüge bestimmt und kann über die Prüfung der Härte des Grundwerkstoffes lokal erfasst werden. Bei Bauteilverbindungen (z.B. Schweißnähte) ist zudem der Übergangsbereich zwischen den Fügeteilen von besonderem Interesse, bei Passungen oder Gleitlagern sind zudem geringe Rauheiten erforderlich, die oft durch mechanische Oberflächen-bearbeitung realisiert werden. Leichtbauweisen können sowohl über hochfeste Stahllegierungen bei geringem Materialeinsatz als auch über Aluminiumlegierungen realisiert werden. Für unterschied-liche Grundwerkstoffe (X2CrNiMo18-14-3, Co-Cr-W-Ni, AlSi10Mg, X5CrNi1810, ferritische Schweiß-nähte) werden an Quer- und Oberflächenschliffen Änderungen im Gefüge, morphologische Besonderheiten, Härteverläufe sowie Änderungen in den Rauheitskennwerten betrachtet, wie sie im Ergebnis mechanischer Oberflächenbearbeitung, bedingt durch den Herstellungsprozess, die Beanspruchung oder den Fügeprozess auftreten. Zur Validierung der Härtebestimmung wurde ein Laborvergleichsversuch an einer MPA-zertifizierten Härtevergleichsplatte und einer 100Cr6 Referenzprobe durchgeführt, den drei bzw. fünf der insgesamt fünf Teilnehmer bestanden. T2 - 55. Materialographie-Tagung CY - Online meeting DA - 29.09.2021 KW - Gleitlinien KW - Rauheit KW - Härteverlauf Schweißnaht KW - Laborvergleich Härte KW - Aluminium PY - 2021 AN - OPUS4-53503 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küchler, S. A1 - Rietz, U. A1 - Lerche, D. A1 - Lange, Thorid A1 - Hielscher, S. A1 - Beck, Uwe T1 - Zentrifugalkraftbasierte Mehrprobenprüfung in einer analytischen Zentrifuge zur Bestimmung von Kleb- und Haftfestigkeiten; Optimierung der Plasmaaktivierung von Polymeren N2 - Das Fügeverfahren Kleben bietet viele Vorteile, wie z.B. das Verbinden unterschiedlicher Materialklassen, geringe thermische Belastung (und damit ggf. verbundene Strukturveränderung/-schwächung) der Fügeteile und eine Lastverteilung über den gesamten Fügebereich. Die Auswahl an verfügbaren Klebstoffen und Vorbehandlungsoptionen sind dabei - wie die Applikationen auch - vielfältig. Es werden vier Applikationsbeispiele zu Referenzklebverbunden aus Edelstahl, zur Plasmaaktivierung von Niedrigenergie-Polymeren, zur Bestimmung der Haftfestigkeit von Lackierungen auf GFK und zur Wirkung von Primern vorgestellt. Einige Polymere weisen z.B. Eigenschaften auf, die eine Herstellung von festen und dauerhaft beanspruchbaren Kleb-verbindungen erschweren. Im Allgemeinen geht dies mit geringen Oberflächenenergien einher. Mittels Oberflächenvorbehandlung, z.B. durch Plasmafeinreinigung bzw. Plasmaaktivierung, können die Grenzflächen solcher Polymere - bezogen auf die Eignung als Fügeteile (Klebfestigkeit) oder als Substrat (Haftfestigkeit) – optimiert bzw. die Oberflächenenergie erhöht werden. Schnelle, zuverlässige und statistisch abgesicherte Prüfverfahren zur Ermittlung von Verbund-eigenschaften sind dabei unverzichtbar. T2 - 35. ak-adp Workshop: Haftung nach Maß – atmosphärische Plasmen für optimierte Adhäsion CY - Nuremberg, Germany DA - 20.11.2019 KW - Adhäsion KW - Mehrprobenprüfung KW - Analytische Zentrifuge KW - Kleb- und Haftfestigkeit PY - 2019 AN - OPUS4-50042 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kormunda, M. A1 - Hertwig, Andreas A1 - Rysanek, P. A1 - Ivanov, L. T1 - Optical and Electrical Properties of reactive/nonreactive Magnetron Deposited SnZnOxCoatings Annealed at Various Temperatures N2 - ZnSnOx coatings were deposited from two 2in magnetron targets made of ZnO and SnO2 connected to DC pulsed and RF power supplies, respectively. The pure Ar and reactive gas mixture Ar/O2 were used. DC pulsed power applied on ZnO target was kept constant 50W 50kHz, 20% d.c. and the RF power applied on SnO2 target was set to values from 0W (pure ZnO deposited) up to 150W (up to 8 at.% of Sn in films). The deposited films were investigated by multiple techniques as deposited at RT as well as after annealing at temperatures 200o C and 450o C. The lower annealing temperature is still compatible with many of common polymeric substrates. The amount of Sn in the films is proportional to applied RF power on SnO2 target. But there is also significant influence of the post Deposition annealing on the film compositions. The ratio Zn/Sn is reduced by the annealing process. Therefore the annealing is promoting the migration of Sn toward the surface and Zn to inside. Moreover the films deposited in oxygen rich reactive gas mixture does not reduces the resistivity with added Sn in contrary to films deposited in Ar where the resistivity was reduced by 5 orders of magnitudes. The plasma parameters were investigated and mean energies of dominant species were in DC pulsed only about 3eV and DC + RF powered plasma up to 15eV. The expected higher energetic particles in the RF influenced plasma deliver an additional energy to the growing film. Therefore, we observed systematic differences between refractive indexes in the films deposited with low RF powered SnO2 magnetron at RT and post-annealed at 200 ° and practically no difference between RT and post-annealed film at higher RF power above 50 W. The XRD results proved the transitions from an amorphous to more crystalline structure by post-annealing of the films. T2 - PSE 2018 - 16th Conference on Plasma Surface Engineering CY - Garmisch-Partenkirchen, Germany DA - 17.09.2018 KW - Reactive sputtering KW - Plasma diagnostics KW - Optical films KW - TCO PY - 2018 AN - OPUS4-46347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kirner, Sabrina V. A1 - Slachciak, Nadine A1 - Elert, Anna Maria A1 - Griepentrog, Michael A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Sahre, Mario A1 - Dörfel, Ilona A1 - Sturm, Heinz A1 - Pentzien, Simone A1 - Koter, Robert A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Tribological performance of titanium samples oxidized by fs-laser radiation, thermal heating, or electrochemical anodization N2 - Commercial grade-1 titanium samples (Ti, 99.6%) were treated using three alternative methods, (i) femtosecond laser processing, (ii) thermal heat treatment, and (iii) electrochemical anodization, respectively, resulting in the formation of differently conditioned superficial titanium oxide layers. The laser processing (i) was carried out by a Ti:sapphire laser (pulse duration 30 fs, central wavelength 790 nm, pulse repetition rate 1 kHz) in a regime of generating laser-induced periodic surface structures (LIPSS). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning setup for the processing of several square-millimeters large surface areas covered homogeneously by these nanostructures. The differently oxidized titanium surfaces were characterized by optical microscopy, micro Raman spectroscopy, variable angle spectroscopic ellipsometry, and instrumented indentation testing. The tribological performance was characterized in the regime of mixed friction by reciprocating sliding tests against a sphere of hardened steel in fully formulated engine oil as lubricant. The specific tribological performance of the differently treated surfaces is discussed with respect to possible physical and chemical mechanisms. KW - Femtosecond laser KW - Titanium KW - Oxidation KW - Friction PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-445609 DO - https://doi.org/10.1007/s00339-018-1745-8 SN - 0947-8396 SN - 1432-0630 VL - 124 IS - 4 SP - 326, 1 EP - 10 PB - Springer-Verlag AN - OPUS4-44560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juds, Carmen A1 - Schmidt, J. A1 - Weller, Michael G. A1 - Lange, Thorid A1 - Beck, Uwe A1 - Conrad, T. A1 - Boerner, H. G. T1 - Combining phage display and next-generation sequencing for materials sciences: A case study on probing polypropylene surfaces N2 - Phage display biopanning with Illumina next-generation sequencing (NGS) is applied to reveal insights into peptide-based adhesion domains for polypropylene (PP). One biopanning round followed by NGS selects robust PP-binding peptides that are not evident by Sanger sequencing. NGS provides a significant statistical base that enables motif analysis, statistics on positional residue depletion/enrichment, and data analysis to suppress false-positive sequences from amplification bias. The selected sequences are employed as water-based primers for PP-metal adhesion to condition PP surfaces and increase adhesive strength by 100% relative to nonprimed PP. KW - Polymers KW - Polypropylene KW - Glue KW - Plastics KW - Surface Activation KW - Primer KW - Peptide Library KW - Epoxy KW - Solid-binding Peptides KW - Functionalization KW - Polymer-binding Peptides KW - Adhesion KW - Material-binding Peptides KW - Adhesives PY - 2020 DO - https://doi.org/10.1021/jacs.0c03482 SN - 0002-7863 SN - 1520-5126 VL - 142 IS - 24 SP - 10624 EP - 10628 PB - ACS CY - Washington, DC, USA AN - OPUS4-51123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Sachse, René A1 - Hertwig, Andreas A1 - Kraehnert, R. T1 - Analysis of elemental composition and porosity of mesoporous IrOx-TiOx thin films by SEM/EDS N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of porous films is affected by properties like porosity, film thickness, chemical composition of the material, as well as the crystallinity of the framework. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution, we characterise thin mesoporous iridium-titanium mixed oxide film properties by electron probe microanalysis (EPMA) with energy-dispersive X-ray spectroscopy (EDS) at an SEM. Mesoporous iridium oxide - titanium oxide (IrOx-TiOx) films were prepared via dip-coating of a solution containing a triblock-copolymer as structure-directing agent, an iridium precursor as well as a titanium precursor in ethanol. IrOx-TiOx films were synthesized with different amounts of iridium and calcined in air. The SEM micrographs reveal for all films the achievement of a well-ordered mesoporous structure and homogeneous films with thicknesses between 67 nm and 152 nm. For the determination of film elemental composition and porosity, EPMA can be used as part of a combined SEM/EDS/STRATAGem analysis. Elemental compositions and mass depositions (in μg cm-2) of IrOx-TiOx films were calculated with the thin film analysis Software STRATAGem via k-values measured with SEM/EDS. Pure bulk Ir, TiO2 and Si were measured as references. The average density of the films was obtained from the mass Deposition and the film thickness as measured by cross-section SEM. The porosity was then extracted from the measured average film density divided by a theoretical bulk density. The latter is calculated from the weight fractions of IrOx and TiOx as determined with STRATAGem and the bulk mass densities of IrO2 and TiO2 (rutil) from literature. The fitting results of the k-values from the STRATAGem software, which are in fair agreement with the measured k-values. The application of the SEM/EDS/STRATAGem approach for accurate porosity determination on pure mesoporous TiOx films and pure porous IrOx films has been recently demonstrated. The porosities of pure IrOx, TiOx and mixed IrOx-TiOx films in this study have been determined. The contribution will assess in detail the advantages and limitations of the combined SEM/EDS/STRATAGem analysis for the morphology and porosity of thin metal oxide films. Moreover, the comparison with other measurement techniques and the combination of datasets from multiple measurements will be discussed. T2 - EMAS 2019 - 16th European Workshop on MODERN DEVELOPMENTS AND APPLICATIONS IN MICROBEAM ANALYSIS CY - Trondheim, Norway DA - 19.05.2019 KW - Thin films KW - Porous layers KW - Electron probe microanalysis (EPMA) KW - Porosity PY - 2019 AN - OPUS4-48107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Sachse, René A1 - Matjacic, L. A1 - McMahon, G. A1 - Hertwig, Andreas A1 - Kraehnert, R. T1 - Correlative analysis of mesoporous thin IrOx-TiOx mixed oxide films for understanding the impact of synthesis conditions N2 - Porous materials play an important role in several fields of technology, especially for energy applications like photovoltaics, electrolysis or batteries. The activity of thin porous films is affected by properties like porosity, film thickness, chemical composition of the material as well as the homogenous dispersion of the active species within the porous matrix. The complex morphology of such porous films constitutes a challenge even for modern analytical techniques and requires new approaches employing the combination/complementation of data of different analytical methods. In this contribution we characterize thin mesoporous iridium-titanium mixed oxide film properties by complementary analysis of SEM/EDS, ToF-SIMS, NanoSIMS, AES and spectroscopic ellipsometry. Mesoporous iridium oxide - titanium oxide (IrOx-TiOx) films can be prepared by a well-established Synthesis route via soft-templating. IrOx-TiOx films are very sensitive to the conditions of synthesis. Analysis by SEM and NanoSIMS imaging suggests IrOx-TiOx films with and without a homogenous dispersion of IrOx within the TiOx film matrix under different synthesis conditions. Auger electron spectroscopy (AES) analysis in the depth-profile mode as well as cross-section line-scan AES measurements of an inhomogeneous IrOx-TiOx film indicate the presence of an IrOx-rich Phase dispersion both at the surface of IrOx-TiOx film as well as within the film. The contribution will assess in detail the sensitivity of the synthesis conditions and the characterization of the thin metal oxide films. Moreover, the correlation between and comparison to other measurement techniques will be discussed. T2 - European Conference on Applications of Surface and Interface Analysis ECASIA 2019 CY - Dresden, Germany DA - 15.09.2019 KW - Mesoporous films KW - Iridium oxide KW - SIMS KW - SEM/EDS KW - Titanium dioxide KW - Ellipsometry KW - Auger Electron Spectroscopy PY - 2019 AN - OPUS4-49234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Sachse, René A1 - Hertwig, Andreas A1 - Kraehnert, R. T1 - Analysis of Mesoporous Iridium Oxide Thin Films by the Combined Methodical Approach SEM/EDS/STRATAGem N2 - For the determination of porosity of Ir oxide thin films, electron probe microanalysis (EPMA) can be used as part of a combined SEM/EDS/STRATAGem analysis. The mass deposition (in μg cm-2) of films was calculated with the analysis software STRATAGem via k-values measured with EDS. The average density of coated films was obtained from the mass deposition and the film thickness as measured by the cross-section SEM. The porosity was calculated by dividing the average film density by the bulk (theoretical) density of the film material. Film porosities were counterchecked by spectroscopic ellipsometry (SE) using the Bruggeman effective medium approximation (BEMA). The results obtained by both analytical approaches/methods used, SEM/EDS/STRATAGem and SE were in good agreement. T2 - Microscopy & Microanalysis 2018 CY - Baltimore, MD, USA DA - 05.08.2018 KW - Electron probe microanalysis (EPMA) KW - Iridium oxide KW - Porous thin films KW - Spectroscopic ellipsometry PY - 2018 AN - OPUS4-46509 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan A1 - Donėlienė1, J. A1 - Rudzikas, M. A1 - Rades, Steffi A1 - Dörfel, Ilona A1 - Peplinski, Burkhard A1 - Sahre, Mario A1 - Pellegrino, F. A1 - Maurino, V. A1 - Ulbikas, J. A1 - Galdikas, A. T1 - Electron Microscopy and X-Ray Diffraction Analysis of Titanium Oxide Nanoparticles Synthesized by Pulsed Laser Ablation in Liquid N2 - A femto-second pulsed laser ablation in liquid (PLAL) procedure for the generation of titanium oxide nanoparticles (NP) is reported with the purpose of understanding morphology and structure of the newly generated NPs. Ablation duration was varied for optimization of NP generation processes between 10 and 90 min. Surface morphology of NPs as well as their size and shape (distribution) were analysed by various complementary electron microscopy techniques, i.e. SEM, TSEM and TEM. The crystalline structure of titanium oxide particles was investigated by XRD and HR-TEM. Concentration of generated titanium oxide NPs in liquid was analysed by ICP-MS. A mix of crystalline (mainly anatase), partly crystalline and amorphous spherical titanium oxide NPs can be reported having a mean size between 10 and 20 nm, which is rather independent of the laser ablation (LA) duration. A second component consisting of irregularly shaped, but crystalline titanium oxide nanostructures is co-generated in the LA water, with more pronounced occurrence at longer LA times. The provenance of this component is assigned to those spherical particles generated in suspension and passing through the converging laser beam, being hence subject to secondary irradiation effects, e. g. fragmentation. T2 - Microscopy & Microanalysis 2018 CY - Baltimore, MD, USA DA - 05.08.2018 KW - Nanoparticles KW - Titanium oxide KW - Laser ablation in liquid KW - Electron microscopy KW - XRD PY - 2018 AN - OPUS4-46502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hielscher-Bofinger, Stefan A1 - Beck, Uwe A1 - Lerche, D. A1 - Rietz, U. T1 - Multiple-sample Testing: Adhesive Strength of Coatings and Bonding Strength of Adhesives evaluated by Centrifugal Adhesion Testing (CAT) N2 - The quantitative determination of adhesion and cohesion properties is a key requirement for adhesive-bonded joints and coated components in both R&D and Quality assurance. Because of the huge variety of layer/substrate Systems in terms of materials and large thickness range, adhesion tests display the same diversity as layer/substrate systems. There are only two tensile testing procedures available, that determine adhesive strength in terms of force per area (N/mm²), the single-sample pull-off test in a tensile testing machine and the multiple-sample-test using the Centrifugal Adhesion Testing (CAT) Technology. The CAT Technology is a testing method which uses centrifugal force as tensile testing force in a multiple-sample arrangement within a drum rotor of a Desktop centrifuge. Hence, the adhesive/bonding strength A/B can be determined on a statistical basis under identical testing conditions for up to eight samples. A variety of examples for bonding strength of adhesives, adhesive strength of coatings and compound strength of composite materials is discussed such as metalto-metal and glass-to-metal bonding, sputtered SiO2-layers on CR39 Polymer and carbon fiber reinforced polymer. T2 - Colloquium Department 6. CY - Berlin, BAM, Germany DA - 03.09.2020 KW - Centrifugal Adhesion Testing (CAT) KW - Adhesive strength KW - Bonding strength KW - Composite strength KW - Interlaboratory comparision PY - 2020 AN - OPUS4-51178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hielscher, Stefan A1 - Beck, Uwe A1 - Lange, Thorid A1 - Grunwald, Daniel A1 - Stockmann, Jörg M. A1 - Lerche, D. A1 - Rietz, U. T1 - Die Zentrifuge als universelles Prüfsystem für Beanspruchungen auf Zug und Druck N2 - Mit der Zentrifugentechnologie ist seit einigen Jahren ein neuartiges Mehr-Proben-Prüf-verfahren auf dem Markt etabliert, welches die klassische Zugprüfung in den Trommelrotor einer Tischzentrifuge überträgt. In der Beanspruchung auf Zug ist die Prüfung der Verbundfestigkeit seit 2017 nach DIN EN ISO/IEC 17025 akkreditiert, wobei die Verbundfestigkeit von Klebungen direkt bestimmt wird und in Abhängigkeit von den Versagensformen Rückschlüsse auf die Klebfestigkeit von Klebstoffen/Klebebändern oder die Haftfestigkeit von Beschichtungen gezogen werden können. Bei der zerstörenden Beanspruchung auf Zug ist zu beachten, dass es sich bei der Verbundfestigkeit um eine Systemeigenschaft handelt, d.h. nicht nur die chemischen und topografischen Oberflächeneigenschaften, sondern auch die plasto-elastischen Volumeneigenschaften des Klebstoffes und der Fügeteile haben Einfluss auf die ermittelten Kennwerte. Dabei ist eine qualitative Bestimmung der Versagensformen und Bruchbilder nach DIN EN ISO 10365 zwingend erforderlich, um eine Aussage über die Art des Versagens treffen zu können. Mit der Erweiterung der Zentrifugentechnologie um Beanspruchungen auf Druck wurde dann der Nachweis erbracht, dass auch die klassische Härteprüfung in einer Zentrifuge als Mehr-Proben-Prüfung durchgeführt werden kann. Im Verbundvorhaben QUO VADIS PLUS werden derzeit invasive Beanspruchungen auf Druck zur Bestimmung der Härte von Materialien, der Kompressibilität von Metallschäumen sowie der Kompaktierbarkeit von Pulvern untersucht, was das Anwendungspotential der Zentrifugentechnologie nochmals erweitert. Dazu gehören auch kombinierte Beanspruchungen wie Zug-Scher- und Druck-Scher-Prüfungen. Die Verbundfestigkeit von CFK-Platten in Abhängigkeit der Beanspruchungsart (Zug vs. Zug-Scher) bzw. der Faserorientierung (0°, 45°, 90°), die Klebfestigkeit von Klebstoffen bzw. Klebebändern auf unterschiedlichen Fügeteilwerkstoffen in Abhängigkeit von der Vorbehandlung, die Haftfestigkeit optischer Schichten auf Kunststoffen, die Bestimmung der Vickers-, Brinell- bzw. Kugeldruck-Härte sowie die Kompressibilität von metallischen Schäumen und Federn werden als ausgewählte Beispiele diskutiert. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Zentrifugentechnologie KW - Haftfestigkeit KW - Härteprüfung KW - Mehr-Proben-Prüfung KW - Beanspruchung auf Zug und Druck PY - 2018 SN - 978-3-00-058187-8 SP - 1 EP - 5 CY - Jena AN - OPUS4-44572 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Ermilova, Elena A1 - Sachse, René A1 - Beck, Uwe T1 - Accuracy, traceability, and standardization in spectroscopic ellipsometry N2 - Ellipsometry has been an extremely successful and fast expanding method in the past decades along with other related techniques using polarisation sensitive measurements. Opening new fields of application for a successful measurement technique brings some requirements and issues that have to be solved. From a metrological point of view, ellipsometry has the problem that uncertainties are difficult to determine for model-based analysis techniques in general. In this presentation, we will explore how the usefulness of polarimetric methods like ellipsometry can be increased. Ellipsometry as a method could profit from several current developments which will be discussed in this presentation: • Standardisation initiatives on national and international level developing standards for best practice when using ellipsometry. A series of at least six standards is currently developed on national German and international level covering different levels of sample complexity. • Projects on traceability of ellipsometry and structured surface spectrometry as well as new dielectric function database initiatives. • Metadata handling and data ontology providing a better framework for exchange and collaborative use of research data. We will also explore the quantification of measurement uncertainty using examples from projects in which BAM is involved. Examples will be presented of multilayer and non-ideal materials as well as the determination of layer properties for technical applications such as thin layer catalysts and complex polymers. The definition of reference materials will be discussed. T2 - 11th Workshop Ellipsometry (WSE 11) CY - Steyr, Austria DA - 06.09.2021 KW - Ellipsometry KW - Uncertainty KW - Surface analytics KW - Data science PY - 2021 AN - OPUS4-53295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Madkour, Sherif A1 - Gawek, Marcel A1 - Schönhals, Andreas T1 - Determination of the glass transition region of thin PVME films by means of spectroscopic ellipsometry N2 - In this presentation, we report on the Determination of the glass transition temperature of thin layers of Polyvinylmethylether (PVME) depending on the thickness of the polymer layer. The glass Transition of thin polymer layers is currently under much investigation due to the nano-confinement effects proposed to appear in dependence on the layer thicknesses in the nm range. The properties of the polymer, the temperature range, as well as the thicknesses range of the polymer layers pose a serious challenge to the investigation by means of spectroscopic ellipsometry. By careful choice of experimental parameters, we were able to investigate the thickness change by temperature of PVME layers in the range between 2 and 300 nm and in the temperature range between 200 K and 340 K. By optimizing the analysis process, we were able to determine Tg values within this parameter range with sufficient accuracy to investigate the Tg change due to confinement effects. Alongside the change of position of the glass transition with thickness, we discuss the details of the ellipsometric analysis and its implications for the resulting thermal properties of the thin polymer layers as well as the accuracy of the Tg value with respect to the method used in the analysis process. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germany DA - 19.03.2018 KW - Polymers KW - PVME KW - Temperature dependent ellipsometry KW - Glass transition PY - 2018 AN - OPUS4-44672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Rosu, D.-M. A1 - Beck, Uwe T1 - Calibration samples and the GUM-compliant determination of uncertainties in ellipsometry N2 - Ellipsometry is well known as a highly sensitive and reproducible surface analysis technique. However, in a context of metrological applications, the most important property of a measurement process is accuracy, relying on statistical precision, (reproducibility) and trueness (in an absolute sense versus a given standard). The latter is much more difficult to achieve. In this presentation, we discuss the possibility of establishing ellipsometry in a diverse metrological landscape by means of defining standard procedures and best practice methodologies for the measurement and for calibration purposes. The most important task of this approach is to determine the model-inherent uncertainty, originating from parameter coupling. We achieve this by means of sensitivity analysis of the parameters resulting from the fit process. We discuss the definition of reference materials by which accuracy can be made available for ellipsometry, passed along between ellipsometry laboratories and for other measurement techniques. The determination of uncertainty is presented in this work for a number of examples involving difficult analysis models employed for samples from different production environments. We present a standardization initiative with the goal to disseminate this work into an international standard alongside an inter-laboratory study comparing the results for complex samples gained by laboratories with different instrumentation. We also present the results gained within EURAMET projects focused on the metrology of materials with strong non-idealities used in photovoltaics and other energy technology. T2 - Workshop Ellipsometry 2018 CY - Chemnitz, Germany DA - 19.03.2018 KW - Ellipsometric metrology KW - Reference samples KW - Reference procedures KW - Standardization PY - 2018 AN - OPUS4-44674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Sachse, René A1 - Hodoroaba, Vasile-Dan A1 - Krähnert, R. T1 - Towards hydrogen economy: multimethod analysis and operando investigation of mesoporous iridium oxides films for electrocatalysis, EMPIR/EURAMET Project HyMet 16ENG03 N2 - In the face of rising energy demand and the impending climate change the development of a sustainable, fossil-free fuel and chemical production is of global importance. One possible goal is the development of electrochemical conversion processes using catalysts. Porous materials play an important role in such energy applications. The key to the development of improved catalysts is a better understanding of the relations between their performance, stability and physico-chemical properties. However, the complex morphology of such catalysts constitutes a challenge even for modern analytical techniques. Spectroscopic ellipsometry (SE) is a versatile method for studying material properties by using appropriate models (e.g. film thickness, optical and electronic properties). The fact that the material properties cannot be taken directly from the measured spectra, the developed models have to be validated. In a first step, the model for the ellipsometric fit studies of a calcination series of mesoporous iridium oxide films (300 – 600 °C) was investigated and validated with respect to their material properties. Moreover, the electronic structures of the catalysts reveal a direct correlation with electrochemical activities. The development of an environmental cell offers the possibility of investigations under real conditions. This will allow changes in the optical and electronic properties during the electrocatalytic oxygen evolution reaction. T2 - HyMet dissemination event CY - Online meeting DA - 17.11.2020 KW - Correlative ex-situ ellipsometric analysis KW - Ellipsometric operando investigation KW - Hydrogen economy KW - Mesoporous iridium oxides films KW - Oxygen evolution reaction PY - 2020 AN - OPUS4-51629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas T1 - Multi-methods surface analysis involving spectroscopic ellipsometry: New measurements for optical and energy applications N2 - Surface analysis is still gaining importance, as most modern technology is in essence surface and thin film technology. In microelectronics and optics but also in many fields of energy storage and conversion, thin surface layers or structured surfaces are key components. Optical surface measurements are useful because of their reliability, robustness, and scalability – properties, which are especially desirable in a production environment. However, many of these methods take require considerable effort in data analysis. Spectroscopic ellipsometry (SE) is maybe the prime example of this class of methods. To combine the advantages of SE with metrological trueness and traceability, we combine it in a group of other methods, such as electron microscopy, instrumental surface analysis, X-ray diffraction. This presentation will give an overview on the principles of SE, its available quantities and the general properties of this measurement technique. Several examples from current and past projects of BAM-6.7 will show how a measurement community involving ellipsometry can benefit many fields of interest, from polymer science to energy applications. In the context of creating a “measurement landscape”, standardisation and standard compliance play an important role. The efforts of BAM in standardisation and accrediting of ellipsometry will be shown demonstrating the possible impact on quality assurance in different fields of technology. T2 - Abteilungskolloquium 2018, BAM CY - BAM, Berlin, Germany DA - 12.12.2018 KW - Spectroscopic ellipsometry KW - Surface analysis KW - Thin film technology KW - Reference materials PY - 2018 AN - OPUS4-47671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hennersdorf, Felix A1 - Weltschev, Margit A1 - Hertwig, Andreas T1 - ATR Investigations into the effect of ageing on HD-PE heating oil storage tanks after a service life of more than 30 years N2 - Heating oil storage tanks made of polyethylene grades have been on the market in Germany since the early 1970s. To ensure safety, their replacement is recommended by tank manufacturers after a period of 30 years. Polyethylene is subject to ageing by alteration of the properties during its life cycle. The degree of degradation and the nature of the process mainly depend on the chemical alteration of the polyethylene, the wall thickness of the tank and the environmental conditions. There are no data available on the long-term behaviour of the polyethylene grades, especially after a service life of more than 30 years. The aim of this investigation was to find a suitable test method to determine the factual degree of damage in comparison to the uncontaminated polyethylene grades. Material data of the used polyethylene grades are available because the BAM was the competent authority for the tests and expert reports for the approval of these tanks until the middle of the 1990s. Therefore, tank sections from the bottom, the shell and the roof of 22 individual storage tanks produced of polyethylene grades A and B have been examined by Melt Flow Rate (MFR) and Attenuated Total Reflectance (ATR). Their service life was in the range between 20 and 41 years. The MFR measurements of the tank sections showed differences in the values depending on the weight which was used (5 kg or 21.6 kg). An increase of the MFR was determined for the samples of polyethylene grade A, whereas a reduction of the MFR values was measured for most samples of polyethylene grade B. This grade is mainly subject to the internal ageing by cross-linkages, increased degree of branched molecules and loss of the plasticizer. ATR analysis exhibits an absorption band at 909 cm‒1 predominantly in samples of polyethylene grade A indicating chain scission and concomitantly formed terminal vinyl groups. This absorption band can be used for the characterization of the ageing of the polyethylene grades. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Heating oil tanks KW - Polyethylene KW - Ageing KW - Service life PY - 2019 AN - OPUS4-49000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Griepentrog, Michael T1 - Estimation of measurement uncertainty of instrumented indentation testing N2 - Some critical discussion of the state of the art of uncertainty evaluationin Instrumented Indentation Testing IIT Nowadays the Instrumented Indentation Testing (IIT), in the nano range often named as nano indention, is one of the most commonly used methods to determine the mechanical properties of materials in the micro and nano range. This method is already extensive standardized in ISO 14577 part 1-4. In the past, the application of this standard in testing praxis shows that the established values have an excellent precision.If an uncertainty is calculated, the range of values within which the true value is asserted to lie with some level of confidencewill be known. In part 1 of ISO 14577 [1] two methods for evaluation of the uncertainty in IIT are mentioned: Method 1 for determining uncertainty considers only those uncertainties associated with the overall measurement performance of the testing machine with respect to the reference blocks. Method 2calculates a combined uncertainty from individual contributions. These may be grouped into random and systematic uncertainties. Both methods will be described in detail using examples from the dailyexperimental praxis. The comparabilityof both methods will be critically discussed. Finally, it will be showedhow the calculated uncertaintiescan be used for performancetests and product specifications. Acknowledgement This work was performed under the support of the EMPIR project 17NRM05Advancing measurement uncertainty̶ comprehensiveexamples for key international standards References [1] ISO 14577 part 1 (2017) T2 - KLA Nanomechanical Testers User Workshop CY - Langen, Germany DA - 02.05.2019 KW - Instrumented Indentation Testing KW - IIT KW - nanoindentation KW - mechanical properties KW - uncertainty KW - performance test KW - product specification PY - 2019 AN - OPUS4-48141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Griepentrog, Michael T1 - Bestimmung der Messunsicherheit bei der instrumentierten Eindringprüfung N2 - In der DIN EN ISO 14577 Metallische Werkstoffe – Instrumentierte Eindringprüfung zur Bestimmung der Härte und anderer Werkstoffparameter sind die Durchführung und Auswertung des Verfahrens, sowie die Kalibrierung der zu verwendenden Prüfmaschine genormt. In dieser Norm werden auch grundsätzliche Aussagen zur Bestimmung der Messunsicherheit gemacht. An Beispielen aus der täglichen Prüfpraxis werden verschiedene Möglichkeiten, aber auch die Grenzen der Bestimmung der Messunsicherheitbei der Instrumentierten Eindringprüfung beschrieben und kritisch diskutiert. T2 - 3. Zwick Roell Symposium –Nanoindentation CY - Ulm, Germany DA - 04.07.2019 KW - ISO 14577 KW - Instrumentierte Eindringprüfung KW - Bestimmung der Messunsicherheit PY - 2019 AN - OPUS4-48431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Griepentrog, Michael T1 - Towards the standardization of dynamic instrumented indentation testing N2 - Nowadays the Instrumented Indentation Testing (IIT) is one of the most commonly used methods to determine the mechanical properties of materials in the nano range. This method is already extensive standardized in EN ISO 14577 part 1-4. Because of the great interest of researchers and industries in investigations of time depending material behavior mostly all suppliers of IIT equipment are offering the possibility of dynamic testing. Realizing this development ISO/TC 164/SC3 Hardness Testing has proposed to start the new standardization project “Linear elastic dynamic instrumented indentation testing DIIT”. The development of this standard is accompanied by the first international intercomparing exercise comparing results of dynamic instrumented indentation testing from testing machines using different hardware solutions and different models for data evaluation. The draft of part 5 of ISO 14577 “Linear elastic dynamic instrumented indentation testing DIIT” specifies verification and calibration of testing machines for carrying out the measurement of the dynamic material response when an oscillatory force or displacement, with amplitudes small in comparison to the prescribed target values, is imparted to the indenter while the indenter is continuously loaded to a prescribed target load or target depth or while the load or displacement is held constant at a prescribed target value. In case of a material showing plastic-elastic behavior, the measured dynamic response is used for continuous evaluation of the dynamic stiffness of the contact as a function of depth and frequency. Using the dynamic stiffness of the contact a reduced dynamic modulus will be calculated. In case of a material showing visco-elastic behavior from the measured dynamic response also the dynamic contact damping coefficient as function of depth and frequency is evaluated continuously. Using dynamic contact stiffness and dynamic contact damping coefficient reduced lost and storage modulus for visco-elastic materials will be calculated. The main normative requirements of the draft will be presented and discussed in the light of the first results of the intercomparing excise. T2 - IIW6, International Indentation Workshop 6 CY - Sapporo, Japan DA - 02.07.2018 KW - ISO 14577 KW - Instrumented indentation testing KW - Nanoindentation KW - IIT KW - Mechanical properties KW - Dynamic testing KW - Visco-elastic KW - Loss module KW - Storage module PY - 2018 AN - OPUS4-45850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is expected to form. These adsorbed layers have shown great potential for technological applications. However, their growth kinetics and molecular dynamics are still not fully understood. This is partially due to the hard accessibility of these layers in thin films. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. First, the growth kinetics of these layers is investigated as a function of annealing times and original film thickness. The thickness, topography and quality of the adsorbed layer is controlled with Atomic Force Microscopy (AFM). Secondly, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor is employed to measure the adsorbed layers with a free surface layer. The results are quantitatively compared and discussed with respect to recently published work. T2 - Meeting of the American Physical Society CY - Los Angeles, CA, USA DA - 05.03.2018 KW - Thin polymeric films KW - Adsorbed layer PY - 2018 AN - OPUS4-44488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is expected to form. These adsorbed layers have shown great potential for technological applications. However, their growth kinetics and molecular dynamics are still not fully understood. This is partially due to the hard accessibility of these layers in thin films. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. First, the growth kinetics of these layers is investigated as a function of annealing times and original film thickness. The thickness, topography and quality of the adsorbed layer is controlled with Atomic Force Microscopy (AFM). Secondly, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor is employed to measure the adsorbed layers with a free surface layer. The results are quantitatively compared and discussed with respect to recently published work. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films KW - Dielectric spectroscopy PY - 2018 AN - OPUS4-44489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Films of P2VP and PVME N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is formed. These adsorbed layers have shown enormous potential for technological applications. Due to the hard accessibility of these layers, their growth kinetics and molecular dynamics are still not fully understood. Here, the irreversibly adsorbed layers of Poly(2-vinylpyridine) (P2VP) and Poly(vinyl methyl ether) (PVME) thin films are revealed by solvent-leaching experiments. The growth kinetics of these layers is investigated as a function of original film thickness and annealing times. The thickness, topography and quality of the adsorbed layer is determined with Atomic Force Microscopy (AFM) and spectroscopic ellipsometry. Additionally, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor (NSC) is employed to measure the adsorbed layers with a free surface layer depending on annealing and solvent-leaching time. The results are quantitatively compared and discussed with respect to recently published work. T2 - Spring Meeting of German Physical Society CY - Regensburg, Germany DA - 31.03.2019 KW - Adsorbed layer KW - Thin polymeric films PY - 2019 AN - OPUS4-47766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gawek, Marcel A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is formed. These adsorbed layers have shown enormous potential for technological applications. The growth kinetics and molecular dynamics of these buried layers in thin films are still not fully investigated due to the hard accessibility. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. The growth kinetics of these layers is investigated as a function of original film thickness and annealing times. The thickness, topography and quality of the adsorbed layer is determined with Atomic Force Microscopy (AFM) and spectroscopic ellipsometry. Additionally, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor (NSC) is employed to measure the adsorbed layers with a free surface layer depending on annealing and solvent-leaching time. The results are quantitatively compared and discussed with respect to recently published work. T2 - Spring Meeting of German Physical Society CY - Regensburg, Germany DA - 31.03.2019 KW - Adsorbed layer KW - Thin polymeric films PY - 2019 AN - OPUS4-47767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritzsche, Sven A1 - Topolniak, Ievgeniia A1 - Weise, Matthias A1 - Sturm, Heinz T1 - Shape deviations of DLW microstructures in dependency of fabrication parameters N2 - Deep understanding of the effects associated with fabrication parameters and their influence on the resulting structures shape is essential for the further development of direct laser writing (DLW). In particular, it is critical for development of reference materials, where structure parameters are precisely fabricated and should be reproduced with use of DLW technology. In this study we investigated the effect of various fabrication and preparation parameters on the structural precision of interest for reference materials. A well-studied photo-curable system, SZ2080 negative photo-resist with 1 wt.% Michler's ketone (Bis) photo-initiator, was investigated in this work. The correlation between applied laser power, laser velocity, fabrication direction on the deviations in the structure shape were observed by means of white light interferometry microscopy. Moreover, influence of slicing and hatching distances as well as prebake time were studied as function of sample shape. Deviations in the structure form between the theoretically expected and the one detected after DLW fabrication were observed in the range up to 15%. The observed shape discrepancies show the essential importance of fine-tuning the fabrication parameter for reference structure production. KW - Direct laser writing KW - Fabrication parameters KW - Structural precision KW - SZ2080 negative photo-resist KW - White light interferometry microscopy PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535906 DO - https://doi.org/10.1088/1361-6439/ac2a14 VL - 31 IS - 12 SP - 1 EP - 8 PB - IOP Science AN - OPUS4-53590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -