TY - JOUR A1 - Straub, Franka A1 - Wirth, Thomas A1 - Hertwig, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Unger, Wolfgang A1 - Böllinghaus, Thomas T1 - Imaging the microstructure of duplex stainless steel samples with TOF-SIMS N2 - Time-of-flight secondary ion mass spectrometry (TOF-SIMS) mappings provide a visualization of the distribution of chemical elements and phases on polished duplex steel surfaces as element and fragment secondary ion signals. The advantage of TOF-SIMS, compared to optical microscopy, is its potential to analyze the chemical composition with a lateral resolution at a submicrometer scale. TOF-SIMS mappings allow distinguishing between ferritic and austenitic phases because of the phase selective detection method without any requirement of etching or other processing. KW - TOF-SIMS mappings KW - Duplex stainless steel KW - Surface analysis KW - Ferritic phase KW - Austenitic phase PY - 2010 UR - http://onlinelibrary.wiley.com/doi/10.1002/sia.3385/pdf DO - https://doi.org/10.1002/sia.3385 SN - 0142-2421 SN - 1096-9918 VL - 42 IS - 6-7 SP - 739 EP - 742 PB - Wiley CY - Chichester AN - OPUS4-21818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Kim, J.W. A1 - Moon, D.W. A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Jordaan, W. A1 - Staden, M.v. A1 - Prins, S. A1 - Wang, H. A1 - Song, X. A1 - Zhang, L. A1 - Fujimoto, T. A1 - Kojima, I. T1 - Final report on key comparison K67 and parallel pilot study P108: measurement of composition of a thin Fe-Ni alloy film N2 - The Key Comparison K67 and the parallel Pilot Study P108 on quantitative analysis of thin alloy films have been completed in the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of these inter-laboratory comparisons is to determine the degree of equivalence in the measurement capability of national metrology institutes (NMIs) and designated institutes (DIs) for the determination of the composition of thin alloy films. The measurand is expressed in atomic percent. A Fe-Ni alloy film with a certified composition was available for the participants of the inter-laboratory comparison. It has been used as a reference specimen to determine the relative sensitivity factors (RSF) of Fe and Ni for the different analytical methods used by the participants to determine the composition of the test sample. As was shown in the preceding Pilot Study P98, the degrees of equivalence in the measurement capabilities of the participants can be improved in that way. The composition of the reference specimen was certified by inductively coupled plasma mass spectrometry (ICP-MS) using the isotope dilution method. The in-depth and lateral homogeneity, determined in terms of elemental composition, of the certified reference sample and the unknown test sample were confirmed by secondary ion mass spectrometry (SIMS) using C60 primary ions by the leading laboratory. Five laboratories participated in the key comparison. Four of them used x-ray photoelectron spectroscopy (XPS) and one Auger electron spectroscopy (AES). One laboratory participated in the parallel P108 pilot study using electron probe micro analysis with an energy-dispersive spectrometer (ED EPMA) and XPS. KW - XPS KW - AES KW - EDX KW - Fe-Ni alloy film KW - Key comparison KW - CCQM PY - 2010 DO - https://doi.org/10.1088/0026-1394/47/1A/08011 SN - 0026-1394 SN - 1681-7575 VL - 47 IS - 1A SP - 08011-1 - 08011-15 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-21045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Unger, Wolfgang A1 - Kim, J.W. A1 - Moon, D.W. A1 - Gross, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Schmidt, Dieter A1 - Wirth, Thomas A1 - Jordaan, W. A1 - van Staden, M. A1 - Prins, S. A1 - Zhang, L. A1 - Fujimoto, T. A1 - Song, X.P. A1 - Wang, H. T1 - Inter-laboratory comparison: quantitative surface analysis of thin Fe-Ni alloy films N2 - An international interlaboratory comparison of the measurement capabilities of four National Metrology Institutes (NMIs) and one Designated Institute (DI) in the determination of the chemical composition of thin Fe-Ni alloy films was conducted via a key comparison (K-67) of the Surface Analysis Working Group of the Consultative Committee for Amount of Substance. This comparison was made using XPS (four laboratories) and AES (one laboratory) measurements. The uncertainty budget of the measured chemical composition of a thin alloy film was dominated by the uncertainty of the certified composition of a reference specimen which had been determined by inductively coupled plasma mass spectrometry using the isotope dilution method. Pilot study P-98 showed that the quantification using relative sensitivity factors (RSFs) of Fe and Ni derived from an alloy reference sample results in much more accurate result in comparison to an approach using RSFs derived from pure Fe and Ni films. The individual expanded uncertainties of the participants in the K-67 comparison were found to be between 2.88 and 3.40 atomic %. The uncertainty of the key comparison reference value (KCRV) calculated from individual standard deviations and a coverage factor (k) of 2 was 1.23 atomic %. KW - Quantification KW - Fe-Ni alloy KW - Uncertainty KW - Key comparison KW - Traceability PY - 2012 DO - https://doi.org/10.1002/sia.3795 SN - 0142-2421 SN - 1096-9918 VL - 44 IS - 2 SP - 192 EP - 199 PB - Wiley CY - Chichester AN - OPUS4-24505 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobol, Oded A1 - Straub, F. A1 - Wirth, Thomas A1 - Holzlechner, G. A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Real Time Imaging of Deuterium in a Duplex Stainless Steel Microstructure by Time-of-Flight SIMS N2 - For more than one century, hydrogen assisted degradation of metallic microstructures has been identified as origin for severe technical component failures but the mechanisms behind have not yet been completely understood so far. Any in-situ observation of hydrogen transport phenomena in microstructures will provide more details for further elucidation of these degradation mechanisms. A novel experiment is presented which is designed to elucidate the permeation behaviour of deuterium in a microstructure of duplex stainless steel (DSS). A hydrogen permeation cell within a TOF-SIMS instrument enables electrochemical charging with deuterium through the inner surface of the cell made from DSS. The outer surface of the DSS permeation cell exposed to the vacuum has been imaged by TOF-SIMS vs. increasing time of charging with subsequent chemometric treatment of image data. This in-situ experiment showed evidently that deuterium is permeating much faster through the ferrite phase than through the austenite phase. Moreover, a direct proof for deuterium enrichment at the austenite-ferrite interface has been found. KW - Characterization and analytical techniques KW - Corrosion KW - Imaging technique KW - Mass spectrometry PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-353872 UR - http://www.nature.com/articles/srep19929 DO - https://doi.org/10.1038/srep19929 SN - 2045-2322 VL - 6 IS - 19929 SP - 1 EP - 7 PB - nature publishing group CY - London, United Kingdom AN - OPUS4-35387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobol, Oded A1 - Holzlechner, Gerald A1 - Nolze, Gert A1 - Wirth, Thomas A1 - Eliezer, D. A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) imaging of deuterium assisted cracking in a 2205 duplex stainless steel microstructure N2 - In the present work, the influence of deuterium on the microstructure of a duplex stainless steel type EN 1.4462 has been characterized by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) supported by scanning electron microscopy (SEM), focused ion beam (FIB), electron back scattered diffraction(EBSD) and energy dispersive x-ray (EDX) investigations. Characterization has been carried out before and after electrochemical charging with deuterium which has been used as a tracer, due to its similar behavior to hydrogen in the steel microstructure. In a first approach, the distribution of the deuterium occurring at temperatures above 58 °C has been visualized. Further it turned out that sub-surface micro blisters are formed in the ferrite-austenite interface, followed by the formation of needle shaped plates and subsequent cracking at the ferrite surface. In the austenite phase, parallel cracking alongside twins and hexagonal close packed (martensitic) regions has been observed. In both phases and even in the apparent interface, cracking has been associated with high deuterium concentrations, as compared to the surrounding undamaged microstructure. Sub-surface blistering in the ferrite has to be attributed to the accumulation and recombination of deuterium at the ferrite-austenite interface underneath the respective ferrite grains and after fast diffusing through this phase. Generally, the present application of chemometric imaging and structural analyses allows characterization of hydrogen assisted degradation at a sub-micron lateral resolution. KW - ToF-SIMS KW - Hydrogen assisted cracking KW - Hydrogen embrittlement KW - SEM KW - FIB KW - EBSD PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0921509316310334 DO - https://doi.org/10.1016/j.msea.2016.08.107 SN - 0921-5093 VL - 676 SP - 271 EP - 277 PB - Elsevier B.V. AN - OPUS4-37298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Investigation of silica nanoparticles by Auger electron spectroscopy (AES) N2 - High-priority industrial nanomaterials like SiO2, TiO2, and Ag are being characterized on a systematic basis within the framework of the EU FP7 research project NanoValid. Silica nanoparticles from an industrial source have been analyzed by Auger electron spectroscopy. Point, line, and map spectra were collected. Material specific and methodological aspects causing the special course of Auger line scan signals will be discussed. KW - Nanoparticles KW - Auger electron spectroscopy KW - Surface analysis PY - 2014 DO - https://doi.org/10.1002/sia.5378 SN - 0142-2421 SN - 1096-9918 VL - 46 IS - 10-11 SP - 952 EP - 956 PB - Wiley CY - Chichester AN - OPUS4-31604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Streeck, C. A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Beckhoff, B. T1 - Qualifying calibration samples for advanced thin film materials characterisation N2 - In this article the question of the certification of calibration samples for the characterisation of advanced thin film materials is addressed within the framework of reliable process control or quality management purposes. Reference measurement techniques can be used in order to address the gap in appropriate certified reference materials (CRMs) for thin film analyses. They allow for qualifying out-of-production samples originating from an operating production line as calibration samples. As a template for this procedure, CIGS [Cu(In,Ga)Se2] layers, that are absorber layers for high efficiency thin-film solar cells, have been used for establishing and validating reference-free X-ray fluorescence (XRF) analysis and Auger-electron spectroscopy (AES) as reference measurement techniques. The focus was on determining the average mole fractions in the CIGS layers obtaining results traceable to the SI unit system. Reference-free XRF is physically traceable and is based upon radiometrically calibrated instrumentation and knowledge of atomic fundamental data. Sputter-assisted AES can be established as a chemically traceable method after careful calibration using a certified reference material (CRM) based on a total number counting method. KW - CIGS KW - X-ray fluorescence (XRF) KW - Auger-electron spectroscopy (AES) PY - 2018 UR - https://www.spectroscopyeurope.com/article/qualifying-calibration-samples-advanced-thin-film-materials-characterisation VL - 30 IS - 1 SP - 11 EP - 14 PB - John Wiley & Sons Ltd CY - Chichester, West Sussex PO19 8SQ, UK AN - OPUS4-44260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Bütefisch, S. A1 - Busch, I. T1 - Lateral resolution delivered by imaging surface-analytical instruments as SIMS, AES and XPS: Application of the BAM-L200 Certified Reference Material and related ISO Standards N2 - The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1-xAs and InxGa1 xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers a plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013. KW - Standardization KW - AES KW - XPS KW - SIMS KW - Lateral resolution KW - Certified reference material PY - 2017 SN - 1341-1756 VL - 24 IS - 2 SP - 123 EP - 128 AN - OPUS4-43138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraffert, K. A1 - Karg, M. A1 - Schmack, R. A1 - Clavel, G. A1 - Boissiere, C. A1 - Wirth,, Thomas A1 - Pinna, N. A1 - Kraehnert, R. T1 - Stabilization of Mesoporous Iron Oxide Films against Sintering and Phase Transformations via Atomic Layer Deposition of Alumina and Silica N2 - The stabilization of crystal phases and nanostructured morphologies is an essential topic in application-driven design of mesoporous materials. Many applications, e.g. catalysis, require high temperature and humidity. Typical metal oxides transform under such conditions from a metastable, low crystal-line material into a thermodynamically more favorable form, i.e. from ferrihy-drite into hematite in the case of iron oxide. The harsh conditions induce also a growth of the crystallites constituting pore walls, which results in sintering and finally collapse of the porous network. Herein, a new method to stabi-lize mesoporous templated metal oxides against sintering and pore collapse is reported. The method employs atomic layer deposition (ALD) to coat the internal mesopore surface with thin layers of either alumina or silica. The authors demonstrate that silica exerts a very strong influence: It shifts hematite formation from 400 to 600 °C and sintering of hematite from 600 to 900 °C. Differences between the stabilization via alumina and silica are rationalized by a different interaction strength between the ALD material and the ferrihydrite film. The presented approach allows to stabilize mesoporous thin films that require a high crystallization temperature, with submonolayer quantity of an ALD material, and to apply mesoporous materials for high temperature applications. KW - Mesoporous oxides KW - Atomic layer deposition KW - Stabilization PY - 2018 DO - https://doi.org/10.1002/admi.201800360 VL - 5 IS - 14 SP - 1800360-1 EP - 1800360-9 PB - Wiley-VCH AN - OPUS4-47869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Investigation of Silica Nanoparticles by Auger Electron Spectroscopy (AES) T2 - PHI European User Meeting 2014 CY - Ismaning, Germany DA - 2014-05-14 PY - 2014 AN - OPUS4-32947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Graf, Nora A1 - Yegen, E. A1 - Lippitz, Andreas A1 - Treu, Dieter A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Optimization of cleaning and aminosilanization protocols for Si wafers to be used as platforms for biochip microarrays by surface analysis (XPS, ToF-SIMS and NEXAFS spectroscopy) N2 - It is known that aminosilanized Si wafers may be used as microarray platforms. Results of an XPS study of a cleaning applied to Si wafers prior to aminosilanization are presented and discussed. Furthermore, the results of an aminosilanization protocol optimized in terms of nitrogen chemistry are described. After optimization of the protocol a free amine content of 94% was reached. The surface chemistry was investigated in this study by using XPS, time of flight (ToF)-SIMS and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Reference to aminosilanization protocols reported in the literature has been made. KW - Aminosilanization KW - Si wafers KW - Microarray KW - XPS KW - ToF-SIMS KW - NEXAFS PY - 2008 DO - https://doi.org/10.1002/sia.2621 SN - 0142-2421 SN - 1096-9918 VL - 40 IS - 3-4 SP - 180 EP - 183 PB - Wiley CY - Chichester AN - OPUS4-17192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Imaging surface analysis: Lateral resolution and its relation to contrast and noise N2 - Lateral resolution, also called image resolution, is the most relevant quality parameter of maps and line scans. Therefore well defined procedures for the determination of lateral resolution are required. In the surface analysis community different definitions of lateral resolution are in use and there is no generally accepted method for the determination of lateral resolution which meets the demands of the state-of-the-art in surface analysis. We propose the determination of lateral resolution by imaging of well defined square-wave gratings with finely graded periods. This method enables the real time estimation of lateral resolution and the adjustment of instrument settings with respect to lateral resolution. The effect of noise and contrast on lateral resolution has been analysed by numerically simulated images of square-wave gratings. A new resolution criterion has been developed which is based on the dip-to-noise ratio and takes into account the sampling step width by introducing a "reduced noise". The contrast transfer function has been introduced and its relation to lateral resolution in the presence of noise was analysed. For that reason an "effective cut-off frequency" was defined which is the reciprocal of the lateral resolution. Normalized values of lateral resolution and their relation to signal-to-noise ratio and sampling step width were given for Gaussian and Lorentzian line spread functions. These values enable the calculation of experimental parameters which are necessary to get a required value of lateral resolution. Finally the successful application of the proposed approach to determine lateral resolution has been demonstrated by ToF-SIMS element mapping of the certified reference material BAM-L200. KW - Auflösungskriterium KW - BAM-L200 KW - Effektive cut-off Funktion KW - Laterale Auflösung KW - Kontrast KW - Kontrasttransferfunktion KW - Linienverwaschungsfunktion KW - Rauschen PY - 2010 DO - https://doi.org/10.1039/c004323k SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 1440 EP - 1452 PB - Royal Society of Chemistry CY - London AN - OPUS4-21875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Österle, Werner A1 - Kaiander, I. A1 - Sellin, R.L. A1 - Bimberg, D. T1 - BAM-L002 - A new type of certified reference material for length calibration and testing of lateral resolution in the nanometre range N2 - A new type of test sample for the determination of lateral resolution in surface analysis is presented. The certified reference material BAM-L002 Nanoscale strip pattern for length calibration and testing of lateral resolution is an embedded cross-section of epitaxially grown layers of AlxGa1-xAs and InxGa1-xAs on GaAs substrate. The surface of the sample provides a flat pattern with strip widths of 0.4-500 nm. The combination of gratings, isolated narrow strips and sharp edges of wide strips offers improved possibilities for the calibration of a length scale, the determination of lateral resolution and the optimization of instrument settings. The feasibility of the reference material for an analysis of lateral resolution is demonstrated for SIMS. PY - 2004 DO - https://doi.org/10.1002/sia.1936 SN - 0142-2421 SN - 1096-9918 VL - 36 SP - 1423 EP - 1426 PB - Wiley CY - Chichester AN - OPUS4-4696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Development of GD-OES standard measurement procedures by using PVD and other referencecoating samples T2 - Expert-Meeting "Depth Profiling", EU Network "Analytical GDS" CY - Dresden, Germany DA - 1999-10-13 PY - 1999 AN - OPUS4-6055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Standard-Messverfahren, Referenzmaterialien für die GD-OES, Aktivitäten der BAM T2 - 7. Deutsches Anwendertreffen "Analytische GDS" CY - Dresden, Germany DA - 2000-10-17 PY - 2000 AN - OPUS4-6122 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Development of reference materials for GD-OES, SNMS, AES and Electron Beam Microanalysis: First results of the VAMAS project, the EC project "MICROLITE" and new EC - "Expression of needs" T2 - EC Network "Analytical GDS": Expert meetings "reference materials for non-conducting and layered samples", Standard procedures; European standards CY - Berlin, Germany DA - 2000-05-03 PY - 2000 AN - OPUS4-6095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Electron-probe MICROanalysis of LIghT Elements; Measurement Methods and Certified Reference Materials (MICROLITE) - Minutes of Progress Meeting: WP1.2 Production of carbide and nitride standards and WP1.4 Stability testing T2 - MICROLITE 7th Progress Meeting, EKO Stahl CY - Eisenhüttenstadt, Germany DA - 2001-10-17 PY - 2001 AN - OPUS4-6901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wirth, Thomas T1 - Electron-probe MICROanalysis of LIghT Elements; Measurement Methods and Certified Reference Materials (MICROLITE) - Minutes of Progress Meeting: WP1.2 Production of carbide and nitride standards and WP1.4 Stability testing T2 - MICROLITE 6th Progress Meeting CY - Palmones, Spain DA - 2001-03-16 PY - 2001 AN - OPUS4-6902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -