TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Kulow, Anicó A1 - Kabelitz, Anke A1 - Grunewald, C. A1 - Seidel, R. A1 - Chapartegui-Arias, Ander A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Beyer, S. T1 - Observation of early ZIF-8 crystallization stages with X-ray absorption spectroscopy N2 - The present study investigates early stages of ZIF-8 crystallization up to 5 minutes post mixing of precursor solutions. Dispersive X-ray Absorption Spectroscopy (DXAS) provides a refined understanding of the evolution of the coordination environment during ZIF-8 crystallization. Linear Combination Fiting (LCF) suggests tetrakis(1-methylimidazole)zinc2+ to be a suitable and stable mononuclear structure analogue for some early stage ZIF-8 intermediates. Our results pave the way for more detailed studies on physico-chemical aspects of ZIF-8 crystallization to better control tailoring ZIF-8 materials for specific applications. KW - In-situ KW - XANES KW - ZIF-8 KW - Crystallization PY - 2020 DO - https://doi.org/10.1039/D0SM01356K SN - 1744-6848 VL - 17 IS - 2 SP - 331 EP - 334 PB - Royal Scociety of Chemistry AN - OPUS4-51723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Fittschen, U. E. A. T1 - Shading Effects in SR-TXRF: Calculations and Experimental Visualization using a Color X-ray Camera T2 - Denver X-ray Conference CY - BIG SKY RESORT, BIG SKY, MONTANA, USA DA - 2014-07-28 PY - 2014 AN - OPUS4-32371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lutz, C. A1 - Breuckmann, M. A1 - Hampel, S. A1 - Kreyenschmidt, M. A1 - Ke, X. A1 - Beuermann, S. A1 - Schafner, K. A1 - Turek, T. A1 - Kunz, U. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Fittschen, U. E. A. T1 - Characterization of Dimeric Vanadium Uptake and Species in Nafion™ and Novel Membranes from Vanadium Redox Flow Batteries Electrolytes N2 - A core component of energy storage systems like vanadium redox flow batteries (VRFB) is the polymer electrolyte membrane (PEM). In this work, the frequently used perfluorosulfonic-acid (PFSA) membrane Nafion™ 117 and a novel poly (vinylidene difluoride) (PVDF)-based Membrane are investigated. A well-known problem in VRFBs is the vanadium permeation through the membrane. The consequence of this so-called vanadium crossover is a severe loss of capacity. For a better understanding of vanadium transport in membranes, the uptake of vanadium ions from electrolytes containing Vdimer(IV–V) and for comparison also V(II), V(III), V(IV), and V(V) by both membranes was studied. UV/VIS spectroscopy, X-ray absorption near edge structure spectroscopy (XANES), total reflection X-ray fluorescence spectroscopy (TXRF), inductively coupled plasma optical emission spectrometry (ICP-OES), and micro X-ray fluorescence spectroscopy (microXRF) were used to determine the vanadium concentrations and the species inside the membrane. The results strongly support that Vdimer(IV–V), a dimer formed from V(IV) and V(V), enters the nanoscopic water-body of Nafion™ 117 as such. This is interesting, because as of now, only the individual ions V(IV) and V(V) were considered to be transported through the membrane. Additionally, it was found that the Vdimer(IV–V) dimer partly dissociates to the individual ions in the novel PVDF-based membrane. The Vdimer(IV–V) dimer concentration in Nafion™ was determined and compared to those of the other species. After three days of equilibration time, the concentration of the dimer is the lowest compared to the monomeric vanadium species. The concentration of vanadium in terms of the relative uptake λ = n(V)/n(SO3 ) are as follows: V(II) [λ = 0.155] > V(III) [λ = 0.137] > V(IV) [λ = 0.124] > V(V) [λ = 0.053] > Vdimer(IV–V) [λ = 0.039]. The results show that the Vdimer(IV–V) dimer Needs to be considered in addition to the other monomeric species to properly describe the transport of vanadium through Nafion™ in VRFBs. KW - MicroXRF KW - VRFB KW - PVDF-based membrane KW - UV/VIS KW - XANES KW - TXRF KW - ICP-OES PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530676 DO - https://doi.org/10.3390/membranes11080576 VL - 11 IS - 8 SP - 576 PB - MDPI AN - OPUS4-53067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Guerra, M.F. A1 - Martinón-Torres, M. A1 - Lemasson, Q. A1 - Moignard, B. A1 - Pacheco, C. A1 - Pichon, L. A1 - Macdonald, L. A1 - Hess, M. A1 - Tissot, I. ED - Guerra, M. F. ED - Martinón-Torres, M. ED - Quirke, S. T1 - Analytical approaches to Egyptian goldwork N2 - The structure and composition of ancient gold objects retain information about their long history of manufacture, from the exploitation of the ore to the finishing touches, as well as evidence of their use, deposition, and degradation. By developing an efficient analytical strategy, it is possible to retrieve that information. This chapter sets the necessary foundation 131to explore fully the analytical results presented in the following chapters of this volume. The techniques employed in the analyses of the Egyptian jewellery are described and the analytical parameters provided. For more established techniques, only brief introductions are presented, while more recent developments are presented in greater detail. KW - Gold KW - Synchrotron KW - D2XRF KW - Egypt PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586039 DO - https://doi.org/10.17863/CAM.99681 SP - 131 EP - 191 AN - OPUS4-58603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - C. Pardo Pérez, L. A1 - Arndt, A. A1 - Stojkovikj, S. A1 - Y. Ahmet, I. A1 - T. Arens,, J. A1 - Dattila, F. A1 - Wendt, R. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Davies, V. A1 - Höflich, K. A1 - Köhnen, E. A1 - Tockhorn, P. A1 - Golnak, R. A1 - Xiao, J. A1 - Schuck, G. A1 - Wollgarten, M. A1 - López, N. A1 - T. Mayer, M. T1 - Determining Structure-Activity Relationships in Oxide Derived CuSn Catalysts During CO2 Electroreduction Using X-Ray Spectroscopy N2 - The development of earth-abundant catalysts for selective electrochemical CO2 conversion is a central challenge. Cu-Sn bimetallic catalysts can yield selective CO2 reduction toward either CO or formate. This study presents oxide-derived Cu-Sn catalysts tunable for either product and seeks to understand the synergetic effects between Cu and Sn causing these selectivity trends. The materials undergo significant transformations under CO2 reduction conditions, and their dynamic bulk and surface structures are revealed by correlating observations from multiple methods—X-ray absorption spectroscopy for in situ study, and quasi in situ X-ray photoelectron spectroscopy for surface sensitivity. For both types of catalysts, Cu transforms to metallic Cu0 under reaction conditions. However, the Sn speciation and content differ significantly between the catalyst types: the CO-selective catalysts exhibit a surface Sn content of 13 at. % predominantly present as oxidized Sn, while the formate-selective catalysts display an Sn content of ≈70 at. % consisting of both metallic Sn0 and Sn oxide species. Density functional theory simulations suggest that Snδ+ sites weaken CO adsorption, thereby enhancing CO selectivity, while Sn0 sites hinder H adsorption and promote formate production. This study reveals the complex dependence of catalyst structure, composition, and speciation with electrochemical bias in bimetallic Cu catalysts. KW - Electrochemical CO2 conversion KW - Cu catalysts KW - X-ray absorption spectroscopy PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547116 DO - https://doi.org/10.1002/aenm.202103328 SN - 1614-6832 VL - 12 IS - 5 SP - 2103328 PB - Wiley-VCH GmbH AN - OPUS4-54711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Rakotondrajoa, A. T1 - Machine learning based quantification of synchrotron radiation-induced X-ray fluorescence measurements - a case study N2 - In this work, we describe the use of artificial neural networks for the quantification of X-ray fluorescence measurements. The training data were generated using Monte Carlo simulation, which avoided the use of adapted reference materials. The extension of the available data set by means of an ANN to generate additional data was demonstrated. Particular emphasis was put on the comparability of simulated and experimental data and how the influence of deviations can be reduced. The search for the optimal hyperparameter, manual and automatic, is also described. For the presented case, we were able to train a network with a mean absolute error of 0.1 weight percent for the synthetic data and 0.7 weight percent for a set of experimental data obtained with certified reference materials. KW - Machine learning KW - BAMline KW - XRF KW - Synchrotron KW - Neural network PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519008 DO - https://doi.org/10.1088/2632-2153/abc9fb SP - 1 EP - 16 PB - IOP Publishing AN - OPUS4-51900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peters, Stefan A1 - Kunkel, Benny A1 - Cakir, Cafer Tufan A1 - Kabelitz, Anke A1 - Witte, Steffen A1 - Bernstein, Thomas A1 - Bartling, Stephan A1 - Radtke, Martin A1 - Emmerling, Franziska A1 - Abdel-Mageed, Ali Mohamed A1 - Wohlrab, Sebastian A1 - de Oliveira Guilherme Buzanich, Ana T1 - Time-, space- and energy-resolved in situ characterization of catalysts by X-ray absorption spectroscopy N2 - A novel setup for dispersive X-ray absorption spectroscopy (XAS) with simultaneous resolution of space, time and energy for in situ characterization of solid materials is demonstrated. KW - Dispersive XAS KW - Catalysis KW - In situ KW - Structure analysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584924 DO - https://doi.org/10.1039/d3cc03277a SN - 1359-7345 SP - 1 EP - 4 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Cakir, Cafer Tufan A1 - Radtke, Martin A1 - Haider, M. Bilal A1 - Emmerling, Franziska A1 - F. M. Oliveira, P. A1 - Michalchuk, Adam T1 - Dispersive x-ray absorption spectroscopy for time-resolved in situ monitoring of mechanochemical reactions N2 - X-ray absorption spectroscopy (XAS) provides a unique, atom-specific tool to probe the electronic structure of solids. By surmounting long-held limitations of powder-based XAS using a dynamically averaged powder in a Resonant Acoustic Mixer (RAM), we demonstrate how time-resolved in situ (TRIS) XAS provides unprecedented detail of mechanochemical synthesis. The use of a custom-designed dispersive XAS (DXAS) setup allows us to increase the time resolution over existing fluorescence measurements from ∼15 min to 2 s for a complete absorption spectrum. Hence, we here establish TRIS-XAS as a viable method for studying mechanochemical reactions and sampling reaction kinetics. The generality of our approach is demonstrated through RAM-induced (i) bottom-up Au nanoparticle mechanosynthesis and (ii) the synthesis of a prototypical metal organic framework, ZIF-8. Moreover, we demonstrate that our approach also works with the addition of a stainless steel milling ball, opening the door to using TRIS-DXAS for following conventional ball milling reactions. We expect that our TRIS-DXAS approach will become an essential part of the mechanochemical tool box. KW - In situ studies KW - Dipsersive XAS KW - Mechanochemistry KW - Time-resolved PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567659 DO - https://doi.org/10.1063/5.0130673 SN - 1089-7690 VL - 157 IS - 21 SP - 1 EP - 12 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-56765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulow, Anicó A1 - Witte, S. A1 - Beyer, S. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, H. A1 - Streli, C. T1 - A new experimental setup for time- and laterally-resolved X-ray absorption fine structure spectroscopy in a 'single shot' N2 - In this work, a new setup for dispersive XAFS measurements is presented. This reproducible and scanningfree setup yields both time- and laterally-resolved XAFS experiments in a ‘single-shot’. It allows a straightforward adjustment for probing different elements covering many relevant applications in materials science. An incoming energetic broadband beam is diffracted by a Si (111) crystal after passing through the sample and collected by an area sensitive detector. Depending on the energy range of the incoming beam, XANES and/or EXAFS spectra can be recorded with a time resolution down to 1 s. The feasibility of this setup was demonstrated at the BAMline at BESSY II (Berlin, Germany) with reference Fe and Cu foils and the results are hereby presented and discussed. Additionally, an application where time resolution on the second scale is required is briefly evaluated. The presented example concerns studying early stages of zinc(II)2-methylimidazolate (ZIF-8) crystallization. This is particularly important for biomedical applications. KW - X-ray spectroscopy KW - X-ray absorption fine structure KW - Time-resolved KW - Laterally-resolved KW - Experimental setup PY - 2019 DO - https://doi.org/10.1039/c8ja00313k SN - 0267-9477 SN - 1364-5544 VL - 34 IS - 1 SP - 239 EP - 246 PB - Royal Society of Chemistry CY - London AN - OPUS4-47207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vincze, L. A1 - Reuter, Dirk T1 - X-ray scattering in X-ray fluorescence spectra with X-ray monochromatic, polarised excitation - modelling, experiment, and Monte-Carlo simulation N2 - A systematic series of measurements has been carried out with monochromatic X-ray excitation with synchrotron radiation in order to check a physical model on X-ray scattering. The model has recently been successfully tested for the case of polychromatic, unpolarised excitation emitted by an X-ray tube. Our main purpose is the modelling of a physical background in X-ray fluorescence spectra, so that improved quantitative results can be achieved especially for strongly scattering specimens. The model includes single Rayleigh and Compton scattering in the specimen, the effect of bound electrons, the challenging Compton broadening and the polarisation degree. Representative specimens, measurement geometries and excitation energies have been selected with synchrotron monochromatic light at BAMline/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model. KW - X-ray scattering KW - Monochromatic excitation KW - Polarisation KW - Modelling KW - Monte-Carlo simulation PY - 2011 DO - https://doi.org/10.1016/j.nimb.2011.04.009 SN - 0168-583X SN - 1872-9584 VL - 269 IS - 13 SP - 1493 EP - 1498 PB - Elsevier CY - Amsterdam AN - OPUS4-23765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hahn, Michael A1 - Buzanich, Günter A1 - Jähn, Katharina A1 - Reinholz, Uwe A1 - Radtke, Martin T1 - Analysis of cobalt deposition in periprosthetic bone specimens by high-resolution synchroton XRF in undecalcified histological thin sections N2 - Increasing numbers of implant revisions are a current clinical issue. Interactions of the endoprosthesis biomaterial with the body affect implantation time by wear processes, i.e. corrosion and abrasion. Previously, cobalt-chrome implants were shown to cause high levels of cobalt ions being deposited in the bone matrix. To determine a poten- tial functional role of these ions on bone homeostasis, we have developed a non-destructive dual analysis of highly sensitive elemental analysis by synchrotron XRF directly in undecalcified histological bone thin sections (4 μm). In this study, samples from 28 bone samples from hip endoprosthesis carriers (Surface Replacement Arthroplasty, metal-on-metal bearing) with an implant lifetime of 17–1750 days were used. Results were compared to age- matched control specimens. The histological analysis identified areas of bone cell activity and assigned them for XRF measurements. Co-Cr wear particles were identified in the bone marrow. In addition, Co ions were highly enriched in the mineralized bone matrix. The cobalt deposits were not homogeneously distributed, and areas of high signal intensity were identified. Co was distinctly deposited in the newly formed osteoid layer, but also within deeper layers of the bone matrix, whereby the Co concentration increased with higher degrees of bone matrix mineralization. In the current study, we determined cobalt accumulations in the bone matrix and showed for the first time via synchrotron XRF with a high spatial resolution direct on histological slides, that cobalt deposits in the mineralized bone matrix in a mineral-specific way that is dependent upon the implant lifetime. KW - Implant material KW - Cobalt deposition KW - Bone matrix KW - High-resolution synchrotron XRF KW - Histology PY - 2019 DO - https://doi.org/10.1016/j.mtla.2019.100290 SN - 2589-1529 VL - 6 SP - 100290, 1 EP - 8 PB - Elsevier Inc. CY - Amsterdam, Niederlande AN - OPUS4-47620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De Samber, B. A1 - Scharf, Oliver A1 - Buzanich, Günter A1 - Garrevoet, J. A1 - Tack, P. A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Evens, R. A1 - De Schamphelaere, K. A1 - Falkenberg, G. A1 - Janssen, C. A1 - Vincze, L. T1 - Three-dimensional X-ray fluorescence imaging modes for biological specimens using a full-field energy dispersive CCD camera N2 - Besides conventional scanning X-ray fluorescence imaging at synchrotron sources, full-field X-ray fluorescence (FF-XRF) imaging techniques that do not implicitly require spatial scanning of the sample have become available. FF-XRF has become achievable thanks to the development of a new type of energy dispersive CCD-based 2D detector, also referred to as a 'color X-ray camera (CXC)' or 'SLcam'. We report on different imaging schemes for biological samples using FF-XRF imaging: (a) 2D 'zoom' imaging with pinhole optics using the 'camera obscura' principle; (b) 2D 'fixed magnification' imaging using magnifying polycapillary optics; and (c) 3D-FF-XRF imaging using an X-ray sheet beam or computed tomography (CT). The different FF-XRF imaging modes are illustrated using the crustacean Daphnia magna, a model organism for investigating the effects of metals on organism/ecosystem health, and foraminifera, a class of amoeboid protist. Detailed analytical characterization of the set-up is performed through analyzing various reference materials in order to determine limits of detection (LODs) and sensitivities. Experiments were performed using the BAMline at the BESSY synchrotron (Berlin, Germany) and using the P06 Hard X-ray Microprobe at the PETRAIII synchrotron (Hamburg, Germany). KW - CXC KW - BAMline KW - Maia detector KW - Synchrotron PY - 2019 DO - https://doi.org/10.1039/c9ja00198k VL - 34 IS - 10 SP - 2083 EP - 2093 PB - Royal Society of Chemistry CY - Cambridge, United Kingdom AN - OPUS4-49359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fittschen, U.E.A. A1 - Möckel, R. A1 - Schreiner, M. A1 - klinger, M. A1 - Radtke, Martin A1 - Meyer, B. A1 - Guhl, S. A1 - Renno, A. A1 - Godinho, J. A1 - Gloaguen, R. A1 - Gutzmer, J. T1 - Bundling analytical capacities to understand phase formation in recycling of functional materials N2 - Transitioning from combustion engine-driven transportation to e-mobility demands a paradigm shift – from a system geared to maximize energy efficiency (i.e. fuel consumption) to a system that may be constrained by the availability of high technology (critical) metals required for electrical energy storage systems and drives. In the wake of these developments efforts in securing new resources of these metals from recycling of end-of-life products are increasing steadily. Recycling of Li-Ion batteries has recently been evaluated. The results pinpoint to a critical need for understanding slag Formation and its dependence on metal components like Mn under extreme conditions. This will allow researchers to predict optimal Operation setting and to react quickly to changing market demands (which may be Li or Co at one point but may also shift to Ni or rare earth elements (REE)). The long-term goal is to control the formation of specific phases in slags allowing for a Maximum yield of elements of interest and optimal recovery in the separation processes that follows. The combination of data on the physical micro structure and local chemistry of the multi-Phase products during and after processing will help to understand and derive thermodynamic and kinetic data on its formation. In this paper we are giving an overview on the analytical challenges and approaches to provide robust data on local element concentration and species (especially Mn which is a common component of next generation Li-ion batteries cathodes), spanning the dimensions from the nanometer scale to the bulk material. The complementary interactions of X-rays and electrons make them ideal probes to collect Interface and “in-depth” information. Before- and -after studies as well as in situ structural changes and Phase (trans)formation, changes in elemental and elemental species (e.g. oxidation state) distribution may be tracked by X-ray diffraction (XRD), X-ray fluorescence microscopy and X-ray Absorption spectroscopy. The application of such advanced analytical tools will not only provide essential clues during early lab-based experiments towards the development of new recycling technologies, but may also be deployed for on-line and in-line monitoring of industrial processes. KW - Synchrotron KW - XANES KW - Slags KW - Battery PY - 2019 DO - https://doi.org/10.4028/www.scientific.net/MSF.959.183 SN - 1662-9752 VL - 959 SP - 183 EP - 190 PB - Trans Tech Publ. AN - OPUS4-48900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Materials research with synchrotron radiation N2 - Synchrotron radiation sources with their unique properties in terms of intensity, polarization and adjustability offer a wide range of possibilities in materials research. A basic introduction about the creation and special properties of synchrotron radiation will be given. Examples of current work at BAMline, the high-energy measuring facility of the Federal Institute for Materials Research and Testing at the synchrotron BESSY, are used to illustrate the possibilities and limitations of existing measuring methods. It will be shown how the formation of corrosion layers can be tracked, how the abrasion of implants leads to the introduction of heavy metals into the surrounding bone matrix and how the detection of smallest impurities in gold is possible by optimizing the measuring conditions. Finally, an outlook at the hardware and software developments to be expected in the coming years is given. T2 - INCT-FNA Symposium 2019 CY - Niteroi, Brazil DA - 27.05.2019 KW - Synchrotron KW - XRF KW - XANES KW - EXAFS KW - TXRF KW - Color X-ray Camera PY - 2019 AN - OPUS4-48897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Machine learning for direct quantification of XRF measurements N2 - In X-ray fluorescence (XRF), a sample is excited with X-rays, and the resulting characteristic radiation is detected to detect elements quantitatively and qualitatively. Quantification is traditionally done in several steps: 1. Normalization of the data 2. Determination of the existing elements 3. Fit of the measured spectrum 4. Calculation of concentrations with fundamental parameters / MC simulations / standard based The problem with standard based procedures is the availability of corresponding standards. The problem with the calculations is that the measured intensities for XRF measurements are matrix-dependent. Calculations must, therefore, be performed iteratively (= time consuming) in order to determine the chemical composition. First experiments with gold samples have shown the feasibility of machine learning based quantification in principle. A large number of compositions were simulated (> 10000) and analyzed with a deep learning network. For first experiments, an ANN (Artificial Neural Network) with 3 hidden layers and 33x33x33 neurons was used. This network learned the mapping of spectra to concentrations using supervised learning by multidimensional regression. The input layer was formed by the normalized spectrum, and the output layer directly yielded the searched values. The applicability for real samples was shown by measurements on certified reference materials. T2 - Denver X-ray Conference CY - Lombard, IL, USA DA - 05.08.2019 KW - Machine learning KW - Artificial intelligence KW - Neural network KW - XRF KW - Synchrotron PY - 2019 AN - OPUS4-48903 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Lippitz, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Schmid, Thomas A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Zirconium permanent modifiers for graphite furnaces used in absorption spectrometry: understanding their structure and mechanism of action N2 - The mechanism of action of zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence on the analytical signal in atomic and molecular absorption spectrometry (AAS/MAS). For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEMEDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. We propose here a mechanism, where ZrO2 acts as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. No evidence of the formation of zirconium carbide was found. Consequently, as the CaF formation is catalysed by a heterogeneous catalyst, surface modifications with ZrO2 nanoparticles and ZrO xerogels were investigated in order to increase the surface area. Their influence was evaluated in the molecule formation of CaF, CaCl, CaBr, and CaI. Graphite furnace modification with zirconium oxide nanoparticles proves to be the best choice for fluorine analysis with a signal enhancement of more than eleven times with respect a non-coated graphite furnace. However, the influence of zirconium modifications in the analytical signals of Cl, and I is lower than the F signals or even negative in case of the Br. Understanding zirconium modifiers as heterogeneous catalysts offers a new perspective to AAS and MAS, and reveals the potential of surface analytical methods for development of improved permanent modifiers and graphite furnace coatings. KW - Zirconium KW - HR-CS-MAS KW - Graphite furnace KW - Nanoparticles KW - Xerogel KW - Calcium monofluoride KW - Absorption spectrometry PY - 2018 UR - https://pubs.rsc.org/en/content/articlelanding/2018/ja/c8ja00190a DO - https://doi.org/10.1039/C8JA00190A SN - 0267-9477 VL - 33 IS - 12 SP - 2034 EP - 2042 PB - Royal Society of Chemistry AN - OPUS4-46775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weber, Kathrin A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Stephan-Scherb, Christiane T1 - A µ‐XANES study of the combined oxidation/sulfidation of Fe–Cr model alloys N2 - The precise analysis of cation diffusion profiles through corrosion scales is an important aspect to evaluate corrosion phenomena under multicomponent chemical load, as during high‐temperature corrosion under deposits and salts. The present study shows a comprehensive analysis of cation diffusion profiles by electron microprobe analysis and microbeam X‐ray absorption near edge structure (µ‐XANES) spectroscopy in mixed oxide/sulfide scales grown on Fe–Cr model alloys after exposing them to 0.5% SO2. The results presented here correspond to depth‐dependent phase identification of oxides and sulfides in the corrosion scales by µ‐XANES and the description of oxidation‐state‐dependent diffusion profiles. Scales grown on low‐ and high‐alloyed materials show both a well‐pronounced diffusion profile with a high concentration of Fe3+ at the gas and a high concentration of Fe2+ at the alloy interface. The distribution of the cations within a close‐packed oxide lattice is strongly influencing the lattice diffusion phenomena due to their different oxidation states and therefore different crystal‐field preference energies. This issue is discussed based on the results obtained by µ‐XANES analysis. KW - X-ray absorption spectroscopy KW - Oxidation KW - Sulfidation PY - 2019 DO - https://doi.org/10.1002/maco.201810644 VL - 70 IS - 8 SP - 1360 EP - 1370 PB - Wiley VCH-Verlag AN - OPUS4-47934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manso, M. A1 - Pessanha, S. A1 - Guerra, M. A1 - Reinholz, Uwe A1 - Afonso, C. A1 - Radtke, Martin A1 - Lourenco, H. A1 - Carvalho, M. L. A1 - de Oliveira Guilherme Buzanich, Ana T1 - Assessment of Toxic Metals and Hazardous Substances in Tattoo Inks Using Sy-XRF, AAS, and Raman Spectroscopy N2 - Synchrotron radiation X-ray fluorescence spectroscopy, in conjunction with atomic absorption and Raman spectroscopy, was used to analyze a set of top brand tattoo inks to investigate the presence of toxic elements and hazardous substances. The Cr, Cu, and Pb contents were found to be above the maximum allowed levels established by the Council of Europe through the resolution ResAP(2008)1 on requirements and criteria for the safety of tattoos and permanent makeup. Raman analysis has revealed the presence of a set of prohibited substances mentioned in ResAP(2008)1, among which are the pigments Blue 15, Green 7, and Violet 23. Other pigments that were identified in white, black, red, and yellow inks are the Pigment White 6, Carbon Black, Pigment Red 8, and a diazo yellow, respectively. The present results show the importance of regulating tattoo ink composition. KW - Synchrotron KW - Tattoo inks KW - XRF KW - Toxic metals KW - Hazardous substances PY - 2019 DO - https://doi.org/10.1007/s12011-018-1406-y VL - 187 IS - 2 SP - 596 EP - 601 PB - Springer AN - OPUS4-47369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Radtke, Martin A1 - Vincze, L. A1 - Rackwitz, Vanessa A1 - Reuter, Dirk T1 - X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation N2 - X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses. KW - X-ray scattering KW - X-ray fluorescence KW - Spectral background KW - Modelling KW - Monte-Carlo simulation PY - 2010 DO - https://doi.org/10.1016/j.nimb.2010.09.017 SN - 0168-583X SN - 1872-9584 VL - 268 IS - 24 SP - 3568 EP - 3575 PB - Elsevier CY - Amsterdam AN - OPUS4-22357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roters, F. A1 - Aslam, A. A1 - Bai, Y. A1 - Büschelberger, M. A1 - Bulert, K. A1 - Butz, A. A1 - Hickel, Tilmann A1 - Jogi, T. A1 - Klitschke, S. A1 - Martin, M. A1 - Meyer, L.-P. A1 - Morand, L. A1 - Nahshon, Y. A1 - Radtke, N. A1 - Saikia, Ujjal A1 - Trondl, A. A1 - Wessel, A. A1 - Zierep, P. A1 - Helm, D. T1 - StahlDigital: Ontology-Based Workflows for the Steel Industry N2 - The innovative strength of the steel industry is based on the mastery of microstructure–property relationships. Digital workflows can largely contribute to this aim by making the complexity of workflows reproducible and their execution user independent. In this work, the tools and workflows developed in the project StahlDigital as part of the German MaterialDigital initiative are presented and application examples are provided. A steel ontology builds the foundation for data collection and storage as well as for the semantic description of experimental and simulation data processing workflows. A dataspace powered by the Dataspace Management System (DSMS) digitally represents such workflows and manages data along them in a Findable, Accessible, Interoperable, Reusable manner aiming to derive new knowledge. Experimental data processed via DSMS can be further evaluated and used as input for simulation workflows. The simulations included in such workflows are run by the workflow system pyiron, which has been semantically extended in StahlDigital for this purpose. KW - Steel KW - Rolling KW - Multiscale simulation KW - Ontology KW - Workflow PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627187 DO - https://doi.org/10.1002/adem.202402148 SN - 1527-2648 SP - 1 EP - 13 PB - Wiley VHC-Verlag AN - OPUS4-62718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -