TY - JOUR A1 - Schukar, Vivien A1 - Köppe, Enrico A1 - Hofmann, Detlef A1 - Mitzkus, Anja A1 - Gong, Xin A1 - Sahre, Mario A1 - Bartholmai, Matthias A1 - Beck, Uwe ED - Emri, Igor T1 - A contribution to intelligent automatic validation of structure-integrated fibre optic strain sensors N2 - An auto-validation tool for the reliability quantification of materials integrated fiber Bragg grating (FBG) strain sensors have been developed and tested. The FBG strain sensor was jacketed with a magnetostrictive layer based on iron-nickel which, when excited by a specific magnetic field, adds an artificial strain to the sensor. The fixed relationship between magnetic induction and wavelength shift of the FBG strain sensor characterizes the bond strength and adhesion between the sensor and the surrounding structure. Due to an easily applicable magnetic field, it is possible to validate the sensor performance in a non-contact, fast way without disturbing the data-acquisition process. T2 - 33nd Danubia Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Fiber Bragg grating KW - Self-diagnosis KW - Magnetostriction KW - Strain KW - Auto-validation PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S2214785317308489 DO - https://doi.org/10.1016/j.matpr.2017.06.073 SN - 2214-7853 VL - 4 IS - 5, Part 1 SP - 5935 EP - 5939 PB - Elsevier Ltd. AN - OPUS4-41583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sahre, Mario T1 - Electroplated magnetostrictive actuator layer enabling the external diagnosis of strain sensors N2 - Embedded fibre-opticaloptical strain sensors are suitable for structural health monitoring. In order to validate long-term performance (e.g.sensors integrated in airplane wings or wind power turbine blades) an external diagnostics is required. A strain-detecting region of the optical fibre, the fibre Bragg grating (FBG, is encased by a magnetostrictive layer system serving as actuator. For the validation of the correct sensor function, an external magnetic field introduces mechanical strain resulting in a defined shift of the Bragg wavelength. The layer system is realized by acombined PVD /ECD process optimized regarding magnetostrictive and mechanical properties. The long -term stability of layer adhesion and actuator function has been verified. T2 - 12. Thementage Grenz- und Oberflächentechnik (ThGOT) und das 5. Kolloquium Dünne Schichten in der Optik CY - Zeulenroda, Germany DA - 14.03.2017 KW - Magnetostrictive actuator layer KW - PVD /ECD process KW - Magnetostrictive layer KW - Strain sensors PY - 2017 AN - OPUS4-41800 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sarma, Dominik A1 - Mielke, Johannes A1 - Sahre, Mario A1 - Beck, Uwe A1 - Hodoroaba, Vasile-Dan A1 - Rurack, Knut T1 - TSEM-based contour analysis as a tool for the quantification of the profile roughness of silica shells on polystyrene core particles N2 - Core-shell (CS) particles with a polymeric core and a silica shell play an important role in the materials and (bio)analytical sciences. Besides the establishment of reliable synthesis procedures, comprehensive particle characterization is essential for batch-to-batch reproducibility and objective performance assessment across architectures, protocols, and laboratories. Particle characterization with respect to size, size distribution, shell thickness and texture, surface area and roughness or materials composition is commonly conducted with different analytical methods, often on different samples. Our approach uses a dual-mode TSEM/SEM set-up with an EDX detector to obtain a complementary data set with sufficient statistical confidence of one and the same sample on a single instrument. Our protocol reveals information about size, size distribution and shell thickness of the various particles employed from overview images, while an increased field of view (FOV) and high-resolution EDX analysis yields detailed information on shell texture and elemental composition. An image analysis tool was developed to derive and quantify the profile roughness of CS particles from individual beads. Comparison with surface roughness data from AFM showed a similar trend in roughness across the series of particles. Reliable classification into smooth and rough is proposed and roughness changes within different particle batches were tracked systematically. KW - Core-shell particles KW - Electron microscopy KW - Transmission mode KW - Roughness KW - Image analysis PY - 2017 DO - https://doi.org/10.1016/j.apsusc.2017.07.099 SN - 0169-4332 SN - 1873-5584 VL - 426 IS - 1 SP - 446 EP - 455 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-42256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Weise, Matthias A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Schukar, Vivien T1 - Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen N2 - In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. T2 - 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium CY - Zeulenroda, Germany DA - 13.03.2018 KW - Magneto-optischer Sensor KW - Faser-Bragg Gitter KW - Magnetostriktive Beschichtung KW - Selbstkalibrierung KW - Bauteilmonitoring PY - 2018 SN - 978-3-00-058187-8 SP - 1 EP - 5 CY - Jena AN - OPUS4-44599 LA - deu 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 - Donėlienė, 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. A1 - Hodoroaba, Vasile-Dan 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(two instruments operated in different geometries) 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. KW - Laser ablation in liquid KW - Nanoparticles KW - Titanium oxide KW - Particle morphology PY - 2018 UR - https://www.cambridge.org/core/journals/microscopy-and-microanalysis/article/electron-microscopy-and-xray-diffraction-analysis-of-titanium-oxide-nanoparticles-synthesized-by-pulsed-laser-ablation-in-liquid/AE368446FAC70E08C514F9AEABFD131B DO - https://doi.org/10.1017/S1431927618009030 VL - 24 IS - S1 (August) SP - 1710 EP - 1711 PB - Cambridge University Press CY - New York, NY, U.S.A. AN - OPUS4-45949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Donėlienė, 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. A1 - Hodoroaba, Vasile-Dan T1 - Morphology and structure of TixOy nanoparticles generated by femtosecond laser ablation in water N2 - In this work 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 byXRD(two instruments operated in different geometries) 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. KW - Titanium oxide KW - Nanoparticles KW - Laser ablation in liquid KW - Particle morphology KW - Nanoparticle structure PY - 2018 DO - https://doi.org/10.1088/2053-1591/aaba56 SN - 2053-1591 VL - 5 IS - 4 SP - 045015-1 EP - 045015-12 PB - IOP Publishing CY - London, UK AN - OPUS4-44678 LA - eng 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 - JOUR A1 - Sachse, René A1 - Pfüger, 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 - Assessing optical and electrical properties of highly active IrOx catalysts for the electrochemical oxygen evolution reaction via spectroscopic ellipsometry N2 - Efficient water electrolysis requires highly active electrodes. The activity of corresponding catalytic coatings strongly depends on material properties such as film thickness, crystallinity, electrical conductivity, and chemical surface speciation. Measuring these properties with high accuracy in vacuum-free and nondestructive methods facilitates the elucidation of structure−activity relationships in realistic environments. Here, we report a novel approach to analyze the optical and electrical properties of highly active oxygen evolution reaction (OER) catalysts via spectroscopic ellipsometry (SE). Using a series of differently calcined, mesoporous, templated iridium oxide films as an example, we assess the film thickness, porosity, electrical resistivity, electron concentration, electron mobility, and interband and intraband transition energies by modeling of the optical spectra. Independently performed analyses using scanning electron microscopy, energy-dispersive X-ray spectroscopy, ellipsometric porosimetry, X-ray reflectometry, and absorption spectroscopy indicate a high accuracy of the deduced material properties. A comparison of the derived analytical data from SE, resonant photoemission spectroscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy with activity measurements of the OER suggests that the intrinsic activity of iridium oxides scales with a shift of the Ir 5d t2g sub-level and an increase of p−d interband transition energies caused by a transition of μ1-OH to μ3-O species. KW - Spectroscopic ellipsometry KW - Electrocatalysis KW - Oxygen evolution reaction KW - Mesoporous iridium oxide films KW - Non-destructive ambient analysis KW - Intrinsic OER activity KW - Complementary methodology and metrology PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516288 DO - https://doi.org/10.1021/acscatal.0c03800 SN - 2155-5435 VL - 10 IS - 23 SP - 14210 EP - 14223 PB - American Chemical Society AN - OPUS4-51628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Florian, Camilo A1 - Fischer, Daniel A1 - Freiberg, K. A1 - Duwe, M. A1 - Sahre, Mario A1 - Schneider, S. A1 - Hertwig, Andreas A1 - Krüger, Jörg A1 - Rettenmayr, M. A1 - Beck, Uwe A1 - Undisz, A. A1 - Bonse, Jörn T1 - Single Femtosecond Laser-Pulse-Induced Superficial Amorphization and Re-Crystallization of Silicon N2 - Superficial amorphization and re-crystallization of silicon in <111> and <100> orientation after irradiation by femtosecond laser pulses (790 nm, 30 fs) are studied using optical imaging and transmission electron microscopy. Spectroscopic imaging ellipsometry (SIE) allows fast data acquisition at multiple wavelengths and provides experimental data for calculating nanometric amorphous layer thickness profiles with micrometric lateral resolution based on a thin-film layer model. For a radially Gaussian laser beam and at moderate peak fluences above the melting and below the ablation thresholds, laterally parabolic amorphous layer profiles with maximum thicknesses of several tens of nanometers were quantitatively attained. The accuracy of the calculations is verified experimentally by high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (STEM-EDX). Along with topographic information obtained by atomic force microscopy (AFM), a comprehensive picture of the superficial re-solidification of silicon after local melting by femtosecond laser pulses is drawn. KW - Femtosecond laser KW - Silicon KW - Amorphization KW - Crystallization KW - Spectroscopic imaging ellipsometry PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523687 UR - https://www.mdpi.com/1996-1944/14/7/1651 DO - https://doi.org/10.3390/ma14071651 SN - 1996-1944 VL - 14 IS - 7 SP - 1651-1 EP - 1651-21 PB - MDPI AG CY - Basel, Switzerland AN - OPUS4-52368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Kai A1 - Mirabella, Francesca A1 - Knigge, Xenia A1 - Mezera, Marek A1 - Weise, Matthias A1 - Sahre, Mario A1 - Wasmuth, Karsten A1 - Voss, Heike A1 - Hertwig, Andreas A1 - Krüger, Jörg A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Chemical and topographical changes upon sub-100-nm laser-induced periodic surface structure formation on titanium alloy: the influence of laser pulse repetition rate and number of over-scans N2 - Titanium and its alloys are known to allow the straightforward laser-based manufacturing of ordered surface nanostructures, so-called high spatial frequency laser-induced periodic surface structures (HSFL). These structures exhibit sub-100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, multi-method characterizations were performed here for HSFL processed on Ti–6Al–4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm, ≈1 ps pulse duration, 1–400 kHz) under different laser scan processing conditions, i.e., by systematically varying the pulse repetition frequency and the number of laser irradiation passes. The sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), tactile stylus profilometry, as well as near-surface chemical analyses hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (ToF-SIMS). This provides a quantification of the laser ablation depth, the geometrical HSFL characteristics and enables new insights into the depth extent and the nature of the non-ablative laser-induced near-surface oxidation accompanying these nanostructures. This allows to answer the questions how the processing of HSFL can be industrially scaled up, and whether the latter is limited by heat-accumulation effects. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Laser processing KW - Hard X-ray photoelectron spectroscopy (HAXPES) KW - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589902 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pssa.202300719 DO - https://doi.org/10.1002/pssa.202300719 SN - 1862-6319 VL - 221 IS - 15 SP - 1 EP - 12 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-58990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, Heike A1 - Knigge, Xenia A1 - Knapic, D. A1 - Weise, Matthias A1 - Sahre, Mario A1 - Hertwig, Andreas A1 - Sacco, A. A1 - Rossi, A. M. A1 - Radnik, Jörg A1 - Müller, Kai A1 - Wasmuth, Karsten A1 - Krüger, Jörg A1 - Hassel, A. W. A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Picosecond laser processing of hierarchical micro–nanostructures on titanium alloy upon pre- and postanodization: morphological, structural, and chemical effects N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser processing step) plays an important role for the response of bone-forming osteoblasts—an effect that can be utilized for improving permanent dental or removable bone implants. For exploring these different surface functionalities, multimethod morphological, structural, and chemical characterizations are performed in combination with electrochemical pre- and postanodization for two different characteristic microspikes covered by nanometric laser-induced periodic surface structures on Ti–6Al–4V upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ≈1 ps pulse duration, 67 and 80 kHz pulse repetition frequency) at two distinct sets of laser fluence and beam scanning parameters. This work involves morphological and topographical investigations by scanning electron microscopy and white light interference microscopy, structural material examinations via X-ray diffraction, and micro-Raman spectroscopy, as well as near-surface chemical analyses by X-ray photoelectron spectroscopy and hard X-ray photoelectron spectroscopy. The results allow to qualify the mean laser ablation depth, assess the spike geometry and surface roughness parameters, and provide new detailed insights into the near-surface oxidation that may affect the different cell growth behavior for pre- or postanodized medical implants. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Hierarchical micro-nanostructures KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Ti-6Al-4V alloy KW - X-ray photoelectron spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601962 DO - https://doi.org/10.1002/pssa.202300920 SN - 1862-6319 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-60196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Habibimarkani, Heydar A1 - Prinz, Carsten A1 - Sahre, Mario A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - CV, TEM, XRD and XPS/HAXPES datasets of FeNi-based nanoparticles for the oxygen evolution reaction N2 - The datasets from Cyclic Voltammetry, Transmision Electron Microscopy, X-ray Diffraction, and (Hard Energy) X-ray Photoelectron Spectroscopy are related to the publication H. Habibimarkani, S.-L. Abram, A. Guilherme Buzanich, C. Prinz, M. Sahre, V.-D. Hodoroaba and J. Radnik "In-depth analysis of FeNi-based nanoparticles for the oxygen evolution reaction" Scientific Reports (2025), https://doi.org/10.1038/s41598-025-92720-3 Details of the materials and the experimental procedures are described in this publications. KW - Oxygen evolution reaction KW - Fe-Ni nanopartices KW - Comprehensive analysis PY - 2025 DO - https://doi.org/10.5281/zenodo.14975964 PB - Zenodo CY - Geneva AN - OPUS4-63335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habibimarkani, Heydar A1 - Abram, Sarah-Luise A1 - de Oliveira Guilherme Buzanich, Ana A1 - Prinz, Carsten A1 - Sahre, Mario A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg T1 - In-depth analysis of FeNi-based nanoparticles for the oxygen evolution reaction N2 - This study investigates the effect of varying iron-to-nickel ratios on the catalytic performance of Fe-Ni oxide nanoparticles (NPs) for the oxygen evolution reaction (OER). Addressing the issue of high energy wastage due to large overpotentials in OER, we synthesized and characterized different NP catalysts with different Fe: Ni oxide ratios. Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), and X-ray Diffraction (XRD) were employed to determine the morphology, elemental and phase composition of the NPs. Furthermore, in-depth profiling with X-ray Photoelectron Spectroscopy (XPS) and Hard X-ray Photoelectron Spectroscopy (HAXPES) revealed that iron predominantly exists as oxide, while nickel exhibits both metallic and oxidic forms depending on the Fe content. XPS indicated an enrichment of iron at the NP surface, whereas HAXPES and EDS data agreed on the bulk stoichiometry. The assessment of the catalytic activity via cyclic voltammetry (CV) showed that the Fe: Ni ratio of 2:3 exhibited superior performance, characterized by lower overpotential and a smaller Tafel slope. KW - Fe-Ni oxide KW - Nanoparticles KW - OER KW - Catalytic performance KW - Cyclic voltammetry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626932 UR - https://www.nature.com/articles/s41598-025-92720-3 DO - https://doi.org/10.1038/s41598-025-92720-3 VL - 15 IS - 1 SP - 1 EP - 17 PB - Springer Nature AN - OPUS4-62693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Zurutuza, Amaia A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Standardized Chemical Composition Analysis of Graphene Oxide Flakes with SEM/EDS and XPS Works Reliably N2 - Suspensions of graphene-related 2D materials (GR2M) are broadly used for further applications like printable electronics. The reliable quantification of the composition of graphene-related 2D materials as liquid suspensions is still a challenging task, which can hinder the commercialisation of the products. Specific parameters to be measured are defined, e.g. the oxygen-to-carbon (O/C) concentration ratio, the trace metal impurities, or the functional groups present, but reference protocols are still missing. One of the central methods for the quantification is X-ray photoelectron spectroscopy (XPS) as a rather expensive method. Therefore, the development of cheaper alternatives is highly desired. One attractive alternative of XPS is energy-dispersive spectroscopy (EDS) which is usually coupled with scanning electron microscopy (SEM). This combination is one of the most widely used methods in analytical laboratories. In this contribution the results of a systematic study on the capability of SEM/EDS to reliably quantify the O/C ratio in a well-defined and well-characterized graphene oxide material are presented. The robustness of the SEM/EDS results obtained at various measurement conditions (various excitation energies) is tested by comparing the results to the established XPS analysis, which has been carried out on the same samples. It is demonstrated that for samples prepared by drop-casting on a substrate, both surface-sensitive XPS analysis and bulk-characterising EDS result in very similar elemental composition of oxygen and carbon for thick spots. Further, the effect of untight deposited material enabling co-analysis of the (silicon) substrate, is evaluated for both methods, XPS and EDS. The last results clearly show the influence of the substrate on the analysis of the results and stressed out the importance of the sample preparation. KW - EDS KW - Light elements KW - XPS/HAXPES KW - Graphene oxide KW - Quantification KW - Standardisation PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.267 VL - 31 IS - 7 SP - 531 EP - 532 PB - Oxford Aacademic AN - OPUS4-63792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Corrao, Elena A1 - Pellegrino, Francesco A1 - Hodoroaba, Vasile-Dan T1 - Wire-Print as a Sample Preparation Procedure Suitable for Accurate Morphological Characterization of Constituent Particles for Graphene-Related 2D-Materials N2 - In this study we have systematically tested the efficacy of a new deposition procedure for graphene-related 2D materials (GR2M’s) from liquid suspension onto a substrate for quantitative analysis of their size and shape distribution with electron microscopy. The technique is an extension of the conventional drop-casting method, and we have designated it “wire-print” deposition. It consists of two steps, first one being usual drop-casting on a copper substrate and second one involving a thin copper wire with a sub-mm diameter being dipped into the deposited droplet and retracted with a corresponding half-spherical droplet attached on its tip and final deposition of this entire nL-amount of suspension onto e.g. a silicon wafer for microscopical, detailed analysis. 11 series of such a wire-print deposition for a graphene-based ink have been considered, whereby various conditions (treatment of the starting suspension) have been experimented with a repetition of up to 10 times per condition, all together 86 spots on a silicon wafer of 10 mm x 10 mm. The evaluation of one series of 8 repeated wire-print depositions reveal that the deposited spots are visualized with SEM. The weak presence of coffee-rings, irregular spot shape, and presence of agglomerates should be noticed. Both the mean value of the 8 ECD distributions and the total number of flakes deposited in each spot show a variance in the range of 17% and 22%, respectively. In the context of accurate analysis of such challenging complex materials these numbers can be considered as excellent and demonstrate the high benefit of the wire-print deposition for accurate morphological measurements on GR2M’s. KW - Sample preparation KW - Imaging KW - 2D materials KW - Morphology KW - Size distribution PY - 2025 DO - https://doi.org/10.1093/mam/ozaf048.219 VL - 31 IS - 7 SP - 436 EP - 437 PB - Oxford Academic AN - OPUS4-63821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - John, Elisabeth A1 - Weise, Matthias A1 - Radnik, Jörg A1 - Stockmann, Jörg Manfred A1 - Lange, Thorid A1 - Sahre, Mario A1 - Hodoroaba, Vasile-Dan T1 - Towards a New Reference Material—Analytical Challenges in Examining High-Entropy Alloy Thin Films N2 - A new high-entropy alloy (HEA) consisting of titanium, chromium, manganese, iron, and nickel was deposited as a thin-film on silicon substrates using magnetron sputtering from a novel segmented target composed of metal stripes. This material was explored with the goal to create a new reference material for surface analysis and evaluation of complex composite materials. The film's morphology was initially characterized by scanning electron microscopy (SEM), followed by crystallographic analysis using X-ray diffraction (XRD) and selected area electron diffraction (SAED). The two-dimensional compositional homogeneity was assessed using a combination of scanning and transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS), X-ray fluorescence (XRF), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and X-ray photoelectron spectroscopy (XPS). The in-depth chemical composition was further analysed using ToF-SIMS and Auger electron spectroscopy (AES). Our findings demonstrate that it is possible to produce thin HEA films with a homogeneous in-depth composition from a segmented target. Notably, despite the fixed composition of the target, we were able to vary the HEA's composition by exploiting inhomogeneities within the magnetrons sputter plasma. Additionally, we successfully created HEA films with significant compositional gradients. T2 - ECASIA CY - Gothenburg, Sweden DA - 10.06.2024 KW - Reference material KW - High-entropy alloy KW - Thin-films PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625777 DO - https://doi.org/10.1002/sia.7387 SN - 1096-9918 SP - 1 EP - 8 PB - Wiley AN - OPUS4-62577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schusterbauer, Robert A1 - Mrkwitschka, Paul A1 - Sahre, Mario A1 - Corrao, Elena A1 - Zurutuza, Amaia A1 - Doolin, Alexander A1 - Pellegrino, Francesco A1 - Radnik, Jörg A1 - Donskyi, Ievgen S. A1 - Hodoroaba, Vasile-Dan T1 - Correlative Chemical Imaging to Reveal the Nature of Different Commercial Graphene Materials N2 - Proper physicochemical characterization of advanced materials and complex industrial composites remains a significant challenge, particularly for nanomaterials, whose nanoscale dimensions and mostly complex chemistry challenge the analysis. In this work, we employed a correlative analytical approach that integrates atomic force microscopy (AFM), scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray spectroscopy (EDS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), Auger electron spectroscopy (AES), and Raman spectroscopy. This combination enables detailed chemical and structural characterization with sub‐micrometer spatial resolution. Three commercial graphene‐based materials of varying complexity were selected and investigated to test the analytical performance of this approach. Furthermore, one of the commercial graphene oxide samples was chemically functionalized via amination and fluorination. This allowed us to assess how surface modifications influence both the material properties and the limits of the applied analytical techniques. KW - Analytical methods KW - Commercial products KW - Correlative analysis KW - Graphene KW - Surface imaging PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654765 DO - https://doi.org/10.1002/smtd.202502344 SN - 2366-9608 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-65476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -