TY - CONF
A1 - Radtke, Martin
T1 - ML@BAMLINE
N2 - An overview of the machine learning methods used at BAMline. Examples of automatic alignment and optimisation based on Gaussian processes are discussed. Quantification of XRF measurements and reconstruction for coded aperture imaging based on neural networks are also presented.
T2 - Machine Learning Workshop BAM
CY - Online meeting
DA - 18.03.2021
KW - Artificial Intelligence
KW - Machine learning
KW - Bayesian Optimization
KW - Gaussian process
KW - Neural Network
PY - 2021
AN - OPUS4-54142
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Radtke, Martin
T1 - SRXRF examples from the BAMline
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.
T2 - Better with Scattering
CY - Online meeting
DA - 16.03.2020
KW - Synchrotron
KW - BAMline
KW - XRF
PY - 2020
AN - OPUS4-51895
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - de O. Primo, J.
A1 - Horsth, D.F.
A1 - de S. Correa, J.
A1 - Das, A.
A1 - Bittencourt, C.
A1 - Umek, P.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Yusenko, Kirill
A1 - Zanetta, C.
A1 - Anaissi, F.J.
T1 - Synthesis and Characterization of Ag/ZnO Nanoparticles for Bacteria Disinfection in Water
N2 - n this study, two green synthesis routes were used for the synthesis of Ag/ZnO nanoparticles, using cassava starch as a simple and low-cost effective fuel and Aloe vera as a reducing and stabilizing agent. The Ag/ZnO nanoparticles were characterized and used for bacterial dis-
infection of lake water contaminated with Escherichia coli (E. coli). Characterization indicated the formation of a face-centered cubic structure of metallic silver nanoparticles with no insertion of Ag into the ZnO hexagonal wurtzite structure. Physicochemical and bacteriological analyses described in “Standard Methods for the Examination of Water and Wastewater” were used to evaluate the efficiency of the treatment. In comparison to pure ZnO, the synthesized Ag/ZnO nanoparticles showed high efficiencies against Escherichia coli (E. coli) and general coliforms present in the lake
water. These pathogens were absent after treatment using Ag/ZnO nanoparticles. The results indicate that Ag/ZnO nanoparticles synthesized via green chemistry are a promising candidate for the treatment of wastewaters contaminated by bacteria, due to their facile preparation, low-cost synthesis,and disinfection efficiency.
KW - Synchrotron
KW - BAMline
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562440
DO - https://doi.org/10.3390/nano12101764
SN - 2079-4991
VL - 12
IS - 10
SP - 1
EP - 18
PB - MDPI
CY - Basel
AN - OPUS4-56244
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Margreiter, R.
A1 - Baumann, J.
A1 - Mantouvalou, I.
A1 - Radtke, Martin
A1 - Reinholz, Uwe
A1 - Strub, E.
T1 - Investigations on fire-gilding
N2 - Fire-gilding is a historic technique for the application of golden layers on a number of different base materials utilizing a gold amalgam. This technique leaves a significant amount of Hg in the golden layer, giving archeometrists a reliable indicator to identify firegildings.
Recent findings on presumably fire-gilded objects have shown in several cases significantly lower Hg content than previously studied objects. This prompted a synchrotron-based X-ray fluorescence investigation into the Hg distribution along the material–gilding interface, as well as a series of measurements regarding the Hg content development in fire-gilded samples during artificial aging. This work presents findings on laboratory-prepared fire-gildings, indicating an Hg enrichment at the interface of firegilded silver samples. Notably, such an enrichment is missing in fire-gilded copper samples. Further, it is confirmed that fire-gilded layers typically do not undercut an Hg bulk content of 5%. In this light, it seems improbable that ancient samples that contain <5% Hg are fire-gilded. The results presented in this study might lead to a non-destructive method to identify the Hg enrichment at the interface. This might be obtained by a combination of different non-destructive measurements and might also work unambiguously in samples in which the gold top layer is altered.
KW - BAMline
KW - X-Ray Fluorescence
KW - Gilding
KW - Depth profile
KW - Archaeometry
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552885
DO - https://doi.org/10.1111/arcm.12797
SN - 0003-813X
SP - 1
EP - 14
PB - Wiley online library
AN - OPUS4-55288
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Iro, M.
A1 - Ingerle, D.
A1 - Radtke, Martin
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Kregsamer, P.
A1 - Streli, C.
T1 - Investigation of polycapillary half lenses for quantitative confocal micro-X-ray fluorescence analysis
N2 - The use of polycapillary optics in confocal micro-X-ray fluorescence analysis (CMXRF) enables the destruction-free 3D investigation of the elemental composition of samples. The energy-dependent transmission properties, concerning intensity and spatial beam propagation of three polycapillary half lenses, which are vital for the quantitative interpretation of such CMXRF measurements, are investigated in a monochromatic confocal laboratory setup at the Atominstitut of TU Wien, and a synchrotron setup on the BAMline beamline at the BESSY II Synchrotron, Helmholtz-Zentrum-Berlin. The empirically established results, concerning the intensity of the transmitted beam, are compared with theoretical values calculated with the polycap software package and a newly presented analytical model for the transmission function.
The resulting form of the newly modelled energy-dependent transmission function is shown to be in good agreement with Monte Carlo simulated results for the complete energy regime, as well as the empirically established results for the energy regime between 6 keV and 20 keV. An analysis of possible fabrication errors was conducted via pinhole scans showing only minor fabrication errors in two of the investigated polycapillary optics. The energy-dependent focal spot size of the primary polycapillary was investigated in the laboratory via the channel-wise evaluation of knife-edge scans. Experimental results are compared with data given by the manufacturer as well as geometric estimations for the minimal focal spot size. Again, the resulting measurement points show a trend in agreement with geometrically estimated results and manufacturer data.
KW - BAMline
KW - Synchrotron
KW - Capillary
KW - confocal
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562430
DO - https://doi.org/10.1107/S1600577522009699
SN - 1600-5775
VL - 29
SP - 1376
EP - 1384
PB - International Union of Crystallography
CY - Chester
AN - OPUS4-56243
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dobosy, Péter
A1 - Nguyen, Hoang Thi Phuong
A1 - Záray, Gyula
A1 - Streli, Christina
A1 - Ingerle, Dieter
A1 - Ziegler, Philipp
A1 - Radtke, Martin
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Endrédi, Anett
A1 - Fodor, Ferenc
T1 - Effect of iodine species on biofortification of iodine in cabbage plants cultivated in hydroponic cultures
N2 - Iodine is an essential trace element in the human diet because it is involved in the synthesis of thyroid hormones. Iodine deficiency affects over 2.2 billion people worldwide, making it a significant challenge to find plant-based sources of iodine that meet the recommended daily intake of this trace element. In this study, cabbage plants were cultivated in a hydroponic system containing iodine at concentrations ranging from 0.01 to 1.0 mg/L in the form of potassium iodide or potassium iodate. During the experiments, plant physiological parameters, biomass production, and concentration changes of iodine and selected microelements in different plant parts were investigated. In addition, the oxidation state of the accumulated iodine in root samples was determined. Results showed that iodine addition had no effect on photosynthetic efficiency and chlorophyll content. Iodide treatment did not considerably stimulate biomass production but iodate treatment increased it at concentrations less than 0.5 mg/L. Increasing iodine concentrations in the nutrient solutions increased iodine content in all plant parts; however, the iodide treatment was 2–7 times more efficient than the iodate treatment. It was concluded, that iodide addition was more favourable on the target element accumulation, however, it should be highlighted that application of this chemical form in nutrient solution decreased the concetrations of selected micoelement concentration comparing with the control plants. It was established that iodate was reduced to iodide during its uptake in cabbage roots, which means that independently from the oxidation number of iodine (+ 5, − 1) applied in the nutrient solutions, the reduced form of target element was transported to the aerial and edible tissues.
KW - BAMline
KW - XANES
KW - Synchrotron
KW - Lodine
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608330
DO - https://doi.org/10.1038/s41598-024-66575-z
VL - 14
IS - 1
SP - 1
EP - 12
PB - Springer Science and Business Media LLC
AN - OPUS4-60833
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Huang, Junhao
A1 - Klahn, Marcus
A1 - Tian, Xinxin
A1 - Bartling, Stephan
A1 - Zimina, Anna
A1 - Radtke, Martin
A1 - Rockstroh, Nils
A1 - Naliwajko, Pawel
A1 - Steinfeldt, Norbert
A1 - Peppel, Tim
A1 - Grunwaldt, Jan‐Dierk
A1 - Logsdail, Andrew J.
A1 - Jiao, Haijun
A1 - Strunk, Jennifer
T1 - Fundamental Structural and Electronic Understanding of Palladium Catalysts on Nitride and Oxide Supports
N2 - The nature of the support can fundamentally affect the function of a heterogeneous catalyst. For the novel type of isolated metal atom catalysts, sometimes referred to as single‐atom catalysts, systematic correlations are still rare. Here, we report a general finding that Pd on nitride supports (non‐metal and metal nitride) features a higher oxidation state compared to that on oxide supports (non‐metal and metal oxide). Through thorough oxidation state investigations by X‐ray absorption spectroscopy (XAS), X‐ray photoelectron spectroscopy (XPS), CO‐DRIFTS, and density functional theory (DFT) coupled with Bader charge analysis, it is found that Pd atoms prefer to interact with surface hydroxyl group to form a Pd(OH)x species on oxide supports, while on nitride supports, Pd atoms incorporate into the surface structure in the form of Pd−N bonds. Moreover, a correlation was built between the formal oxidation state and computational Bader charge, based on the periodic trend in electronegativity.
KW - BAmline
KW - XANES
KW - Catalyst
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608341
DO - https://doi.org/10.1002/anie.202400174
SN - 1433-7851
VL - 63
IS - 20
SP - 1
EP - 9
PB - Wiley
AN - OPUS4-60834
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Förste, F.
A1 - Bauer, L.
A1 - Streeck, C.
A1 - Radtke, Martin
A1 - Reinholz, Uwe
A1 - Kadow, D.
A1 - Keil, C.
A1 - Mantouvalou, I.
T1 - Quantitative Analysis and 2D/3D Elemental Imaging of Cocoa Beans Using X‑ray Fluorescence Techniques
N2 - As an important raw material for the confectionery industry, the cocoa bean (Theobroma cacao L.) has to meet certain legal requirements in terms of food safety and maximum contaminant levels in order to enter the cocoa market. Understanding the enrichment and distribution of essential minerals but also toxic metals is of utmost importance for improving the nutritional quality of this economically important raw food material. We present three X-ray fluorescence (XRF) techniques for elemental bio-imaging of intact cocoa beans and one additional XRF technique for quantitative analysis of cocoa pellets. The interrelation of all the methods presented gives a detailed picture of the content and 3D-resolved distribution of elements in complete cocoa beans for the first time.
KW - BAMline
KW - Synchrotron
KW - XRF
KW - CXC
KW - Cocoa
PY - 2023
DO - https://doi.org/10.1021/acs.analchem.2c05370
VL - 95
SP - 5627
EP - 5635
PB - ACS Publications
AN - OPUS4-57832
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grengg, C.
A1 - Gluth, Gregor
A1 - Mittermayr, F.
A1 - Ukrainczyk, N.
A1 - Bertmer, M.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Leis, A.
A1 - Dietzel, M.
T1 - Deterioration mechanism of alkali-activated materials in sulfuric acid and the influence of Cu: A micro-to-nano structural, elemental and stable isotopic multi-proxy study
N2 - In this study, a multi-proxy approach combining 29Si, 27Al and 1H MAS-NMR, FEG-EPMA, XANES at the Cu K-edge and XRD analytics with hydrochemical tools such as ICP-OES analyses, oxygen-isotope signatures, and thermodynamic modelling was applied to K-silicate-activated metakaolin specimens - with and without CuSO4·5H2O addition - exposed to sulfuric acid at pH = 2 for 35 days. The results revealed a multistage deterioration mechanism governed by (i) acid diffusion, (ii) leaching of K-A-S-H, (iii) microstructural damage related to precipitation of expansive (K,Ca,Al)-sulfate-hydrate phases (iv) complete dissolution of the K-A-S-H framework, (v) and formation of silica gel in the outermost corroded regions. Copper ions were mainly located in layered spertiniite-chrysocolla-like phases in the as-cured materials. The results demonstrate an overall negative effect of Cu addition on chemical material durability, implying that the reported higher durability of Cu-doped AAM in biocorrosion environments can be best explained by bacteriostatic effects.
KW - Alkali-activated materials
KW - Acid resistance
KW - Microbially induced corrosion
KW - MIC
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520567
DO - https://doi.org/10.1016/j.cemconres.2021.106373
SN - 0008-8846
VL - 142
SP - 1
EP - 15
PB - Elsevier
CY - Oxford
AN - OPUS4-52056
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kulow, Anicó
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Reinholz, Uwe
A1 - Streli, C.
A1 - Radtke, Martin
T1 - On the way to full-field X-ray fluorescence spectroscopy imaging with coded apertures
N2 - Imaging with X-rays is a challenging field, due to the optical properties of X-rays. The fabrication of appropriate optics is usually expensive and requires an elaborate manufacturing process. One simpler and less expensive possibility of imaging high energy radiation is coded aperture imaging, a technique well established in astrophysics and also used in nuclear medicine or radiation detection, e.g., for nuclear decommissioning. Our aim is to adapt coded aperture imaging for X-ray fluorescence spectroscopy in the nearfield. In this work we show theoretical considerations and preliminary simulations of Image formation through a coded aperture and three different reconstruction methods to prepare the experiments. We used a new mask based on an inverted modified uniformly redundant array (MURA) that could be used for the construction of a decoding mask for all investigated geometrical arrangements.
The most commonly used reconstruction method, convoluting the detected image with a Decoding mask, does not always deliver satisfactory results. This is more noticeable for small distances between the object, mask and detector. Hence, we developed two new reconstruction methods, one based on iterative algebraic optimization and another one based on a genetic algorithm. Both show good performance even in those cases where the convolution method fails. This provides a basis for further investigations of the ideal parameters for near field coded aperture imaging and refinements of the algorithms. We performed first measurements with a coded aperture at the BAMline at BESSY II and could successfully reconstruct a test object from the obtained recorded images.
KW - X-ray fluorescence spectroscopy
KW - Coded aperture
KW - Imaging
KW - Iterative reconstruction
PY - 2020
DO - https://doi.org/10.1039/c9ja00232d
VL - 35
IS - 2
SP - 347
EP - 356
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-50459
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
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 - 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 CuSn 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 - 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 - CONF
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Emmerling, Franziska
ED - Rogge, Andreas
ED - Meng, Birgit
T1 - Exploring new materials for Green Intelligent Building - How can our BAMline help?
N2 - In the scope of exploring and characterizing new materials related to Green Intelligent Building (GIB), we will provide an overview of the X-ray spectroscopy and diffraction analytical methods available at the BAMline /1/. and Myspot beamlines. These are two universal beamlines at the Berlin Synchrotron BESSY-II, where BAM has access and supervision role. Overarching electronic and structural properties at different time and length scales, such measurements enable a real-time characterization of materials properties. We will show-case in situ and ex situ deterioration and hydration studies on cement-based constructure materials.
T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building
CY - Berlin, Germany
DA - 16.10.2024
KW - BAMline
KW - Scope of exploring
KW - Green intelligent building
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612882
SN - 978-3-9818564-7-7
SP - 30
EP - 36
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-61288
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 - Cakir, Cafer Tufan
A1 - Bogoclu, Can
A1 - Emmerling, Franziska
A1 - Streli, Christina
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
T1 - Machine learning for efficient grazing-exit x-ray absorption near edge structure spectroscopy analysis: Bayesian optimization approach
N2 - In materials science, traditional techniques for analyzing layered structures are essential for obtaining information about local structure, electronic properties and chemical states. While valuable, these methods often require high vacuum environments and have limited depth profiling capabilities. The grazing exit x-ray absorption near-edge structure (GE-XANES) technique addresses these limitations by providing depth-resolved insight at ambient conditions, facilitating in situ material analysis without special sample preparation. However, GE-XANES is limited by long data acquisition times, which hinders its practicality for various applications. To overcome this, we have incorporated Bayesian optimization (BO) into the GE-XANES data acquisition process. This innovative approach potentially reduces measurement time by a factor of 50. We have used a standard GE-XANES experiment, which serve as reference, to validate the effectiveness and accuracy of the BO-informed experimental setup. Our results show that this optimized approach maintains data quality while significantly improving efficiency, making GE-XANES more accessible to a wider range of materials science applications.
KW - Machine Learning
KW - GE-XANES
KW - Bayesian Optimization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603955
DO - https://doi.org/10.1088/2632-2153/ad4253
VL - 5
IS - 2
SP - 1
EP - 12
PB - IOP Publishing
AN - OPUS4-60395
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Senges, Gene
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Lindič, Tilen
A1 - Gully, Tyler A.
A1 - Winter, Marlon
A1 - Radtke, Martin
A1 - Röder, Bettina
A1 - Steinhauer, Simon
A1 - Paulus, Beate
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Unravelling highly oxidized nickel centers in the anodic black film formed during the Simons process by in situ X-ray absorption near edge structure spectroscopy
N2 - The electrofluorination after Simons has been used for the last century to produce everyday life materials. An in situ XANES investigation of the controversially debated black film apparent in the Simons process revealed high-valent nickel centers.
KW - Synchrotron
KW - BAMline
KW - XANES
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608366
DO - https://doi.org/10.1039/d3sc06081k
SN - 2041-6520
VL - 15
IS - 12
SP - 4504
EP - 4509
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60836
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -