TY - CONF
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - Exploring new materials for Green Intelligent Building how can our BAMline help
N2 - With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. Synchrotron X-ray based methods enable unique tools to probe materials properties via e.g. X-ray spectroscopy and diffraction methods. The BAM plays a central role in this highly collaborative research. The BAMline, a real-life sample materials research beamline, at the Berlin Synchrotron BESSY-II, provides unique insights into materials’ electronic and chemical structure at different time and length scales1. This enables real-time optimization of material properties and performance for various applications, such as energy storage and conversion, catalysis, and deterioration resistance.
T2 - DAfStb-Kolloquium
CY - Berlin, Germany
DA - 16.10.2024
KW - XAS
KW - Time-resolved studies
KW - Binding materials
KW - Cements
PY - 2024
AN - OPUS4-61616
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - Time resolved in situ monitoring of mechanochemical transformations by X-ray absorption spectroscopy (XAS)
N2 - Mechanochemical reactions promise a new direction for environmentally benign preparation of materials, and has been dubbed by IUPAC as one of the 10 chemical innovations that will change our world. Despite this significant promise, very little is known about the mechanisms that drive mechanochemical transformations, posing significant barriers to realizing their full potential. To this end, there is growing need to follow mechanochemical reactions in situ and in real time. We here describe advances in the development and application of XAS methods to monitor material synthesis in real time under mechanochemical conditions. We demonstrate the generality of our approaches by describing mechanochemical syntheses of materials by both vibratory ball milling and by Resonant Acoustic Mixing (RAM), where a time resolution of 1 second is for a whole XAS spectrum was achieved. Moreover, we describe how spectroscopic methods can be coupled to diffraction-based approaches, thereby providing new dimensions in understanding mechanochemical synthesis.
T2 - European Conference on X-ray Spectrometry 2022
CY - Bruges, Belgium
DA - 27.06.2022
KW - XAS
KW - Mechanochemictry
KW - Time resolved
KW - In situ
PY - 2022
AN - OPUS4-56258
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - S2XAFS: Time-resolved X-ray absorption spectroscopy in a ‘single-shot’ – First in situ applications
N2 - The newly developed EXAFS set-up comprises both time- and spatially-resolved EXAFS information simultaneously in a single-shot. This facile, stable and scanningless set-up was tested at the BAMline @ BESSY-II (Berlin, Germany). The pri-mary broadband beam is generated by a filter/X-ray-mirror combination (bandpass). The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by an area sensitive detector, in a theta - 2 theta geometry. The first in situ measurements were successfully carried out and hereby presented. The case-study deals with research on Zn-based Metal-Organic-Frameworks (MOFs) that have potential for medi-cal/pharmaceutical applications. This hot topic of MOF research targets encapsulation of therapeutically relevant bio-macromolecules (e.g. Enzymes) for drug delivery applications. Questions regarding the influence of proteins on the coor-dination of Zn during MOF crystal growth and within the final MOF can be answered with this new setup. We were able to track structural changes within a 1s time resolution.
T2 - CSI XL Conference
CY - Pisa, Italy
DA - 12.06.2017
KW - Single-shot EXAFS
KW - In situ characterization
KW - Biomedical applications
PY - 2017
AN - OPUS4-40683
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - ´Single-shot´XANES with a Color X-ray Camera (CXC) at the BAMline (BESSY-II)
T2 - XAFS 16
CY - Karlsruhe, Germany
DA - 2015-08-24
PY - 2015
AN - OPUS4-34042
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Smerechuk, Anastasiia
A1 - Guilherme Buzanich, Ana
A1 - Büchner, Bernd
A1 - Wurmehl, Sabine
A1 - Morrow, Ryan
T1 - Synthesis and properties of Sr2La2NiW2O12, a new S = 1 triangular lattice magnet
N2 - Magnetic materials featuring triangular arrangements of spins are frequently investigated as platforms hosting magnetic frustration. Hexagonal perovskites with ordered vacancies serve as excellent candidates for two-dimensional triangular magnetism due to the considerable separation of the magnetic planes. In this work, the effects of chemical pressure on the ferromagnetic ground state of Ba2La2NiW2O12 by substitution of Ba2+ with Sr2+ to produce Sr2La2NiW2O12 are investigated. The two materials are characterized using synchrotron-based XRD, XANES and EXAFS in addition to magnetometry in order to correlate their crystal structures and magnetic properties. Both materials form in space group R 3, yet as a result of the enhanced bending of key bond angles due to the effects of chemical pressure, the T C value of the magnetic Ni2+ sublattice is reduced from ∼6 K in Ba2La2NiW2O12 to 4 K in Sr2La2NiW2O12.
KW - XRD
KW - Magnetic materials
KW - EXAFS
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652982
DO - https://doi.org/10.1107/S2052520624007091
SN - 2052-5206
VL - 80
IS - 5
SP - 467
EP - 473
PB - International Union of Crystallography (IUCr)
AN - OPUS4-65298
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fittschen, U.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Böttger, S.
A1 - Rosenberg, D.
A1 - Menzel, M.
A1 - Jensen, W.
A1 - Busker, M.
A1 - Gotlib, Z.
A1 - Radtke, Martin
A1 - Riesemeier, Heinrich
A1 - Wobrauschek, P.
A1 - Streli, C.
ED - de Oliveira Guilherme Buzanich, Ana
T1 - A setup for synchrotron-radiation-induced total reflection X-ray fluorescence and X-ray absorption near-edge structure recently commissioned at BESSY II BAMline
N2 - An automatic sample changer chamber for total reflection X-ray fluorescence (TXRF) and X-ray absorption near-edge structure (XANES) analysis in TXRF geometry was successfully set up at the BAMline at BESSY II. TXRF and TXRF-XANES are valuable tools for elemental determination and speciation, especially where sample amounts are limited (<1 mg) and concentrations are low (ng ml⁻¹ to μg ml⁻¹). TXRF requires a well defined geometry regarding the reflecting surface of a sample carrier and the synchrotron beam. The newly installed chamber allows for reliable sample positioning, remote sample changing and evacuation of the fluorescence beam path. The chamber was successfully used showing accurate determination of elemental amounts in the certified reference material NISTwater 1640. Low limits of detection of less than 100 fg absolute (10 pg ml⁻¹) for Ni were found. TXRF-XANES on different Re species was applied. An unknown species of Re was found to be Re in the +7 oxidation state.
KW - TXRF
KW - TXRF-XANES
KW - Sample changer
KW - BAMline
KW - Re-XANES
PY - 2016
DO - https://doi.org/10.1107/S1600577516001995
SN - 1600-5775
VL - 23
IS - 3
SP - 820
EP - 824
PB - International Union of Crystallography
AN - OPUS4-38656
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hachmöller, O.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Aichler, M.
A1 - Radtke, Martin
A1 - Dietrich, D.
A1 - Schwamborn, K.
A1 - Lutz, L.
A1 - Werner, M.
A1 - Sperling, M.
A1 - Walch, A.
A1 - Karst, U.
T1 - Elemental bioimaging and speciation analysis for the investigation of Wilsons disease using μXRF and XANES
N2 - A liver biopsy specimen from a Wilson’s disease (WD) patient was analyzed by means of micro-X-ray fluorescence (mXRF) spectroscopy to determine the elemental distribution. First, bench-top mXRF was utilized for a coarse scan of the sample under laboratory conditions. The resulting distribution maps of copper and iron enabled the determination of a region of interest (ROI) for further analysis. In order to obtain more detailed elemental information, this ROI was analyzed by synchrotron radiation (SR)-based mXRF with a beam size of 4 mm offering a resolution at the cellular level. Distribution maps of additional elements to copper and iron like zinc and manganese were obtained due to a higher sensitivity of SR-mXRF. In addition to this, X-ray absorption near edge structure spectroscopy (XANES) was performed to identify the oxidation states of copper in WD. This speciation analysis indicated a mixture of copper(I) and copper(II) within the WD liver tissue.
KW - progressive hepatolenticular degeneration
KW - mXRF Micro-X-ray fluorescence spectroscopy
KW - XANES X-ray absorption near edge structure spectroscopy
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-360811
DO - https://doi.org/10.1039/C6MT00001K
SN - 1756-5901
SN - 1756-591X
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-36081
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rauwolf, M.
A1 - Turyanskaya, A.
A1 - Roschger, A.
A1 - Prost, J.
A1 - Simon, R.
A1 - Scharf, O.
A1 - Radtke, Martin
A1 - Schoonjans, Tom
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Klaushofer, K.
A1 - Wobrauschek, P.
A1 - Hofstaetter, J. G.
A1 - Roschger, P.
A1 - Streli, C.
T1 - Synchrotron radiation micro X-ray fluorescence spectroscopy of thin structures in bone samples: comparison of confocal and color X-ray camera setups
N2 - In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-mXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution. It was demonstrated that the ideal method depends on the element of interest. Although for Ca (a major constituent of the bone with a low energy of 3.69 keV for its K alpha XRF line) the color X-ray camera provided a higher resolution in the plane, for Zn (a trace element in bone) only the confocal SR-µXRF setup was able to sufficiently image the distribution.
KW - Synchrotron
KW - BAMline
KW - BESSY
KW - XRF
KW - X-ray Color Camera
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-391944
DO - https://doi.org/10.1107/S1600577516017057
SN - 1600-5775
VL - 24
SP - 307
EP - 311
PB - International Union of Crystallography
AN - OPUS4-39194
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 - Dubey, A.
A1 - Hon Keat, C.
A1 - Shvartsman, V.
A1 - Yusenko, Kirill
A1 - Escobar, M.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Hagemann, U.
A1 - Kovalenko, S.
A1 - Stächler, J.
A1 - Lupascu, D.
T1 - Mono-, Di-, and Tri-valent Cation Doped BiFe0.95Mn0.05O3 Nanoparticles: Ferroelectric Photocatalysts
N2 - The ferroelectricity of multivalent co-doped Bismuth ferrite (BiFeO3; BFO) nanoparticles (NPs) is revealed and utilized for light photocatalysis exploiting their narrow electronic band gap. The photocatalytic activity of ferroelectric photocatalysts BiFe0.95Mn0.05O3 (BFM) NPs and mono-, di-, or tri-valent cations (Ag+, Ca2+, Dy3+; MDT) co-incorporated BFM NPs are studied under ultrasonication and in acidic conditions. We find that such doping enhances the photocatalytic activity of the ferroelectric NPs approximately three times. The correlation of the photocatalytic activity with structural, optical, and electrical properties of the doped NPs is established. The increase of spontaneous polarization by the mono- and tri-valent doping is one of the major factors in enhancing the photocatalytic performance along with other factors such as stronger light absorption in the visible range, low recombination rate of charge carriers and larger surface area of NPs. A-site doping of BFO NPs by divalent elements suppresses the polarization, whereas trivalent (Dy3+) and monovalent (Ag+) cations provide an increase of polarization. The depolarization field in these single domain NPs acts as a driving force to mitigate recombination of the photoinduced charge carriers.
KW - Piezoresponse
KW - Bismuth Ferrite
KW - Nanoparticles
KW - Photocatalysis
KW - Ferroelectric
KW - Polarization
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557230
DO - https://doi.org/10.1002/adfm.202207105
SN - 1616-301X
SP - 1
EP - 16
PB - Wiley
AN - OPUS4-55723
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 - 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 - Gomes, Bruna F.
A1 - Prokop, Martin
A1 - Bystron, Tomas
A1 - Loukrakpam, Rameshwori
A1 - Melke, Julia
A1 - Lobo, Carlos M. S.
A1 - Fink, Michael
A1 - Zhu, Mengshu
A1 - Voloshina, Elena
A1 - Kutter, Maximilian
A1 - Hoffmann, Hendrik
A1 - Yusenko, Kirill V.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Röder, Bettina
A1 - Bouzek, Karel
A1 - Paulus, Beate
A1 - Roth, Christina
T1 - Following Adsorbed Intermediates on a Platinum Gas Diffusion Electrode in H3PO3-Containing Electrolytes Using In Situ X-ray Absorption Spectroscopy
N2 - One of the challenges of high-temperature polymer electrolyte membrane fuel cells is the poisoning of the Pt catalystwith H3PO4. H3PO4 is imbibed into the routinely used polybenzimidazole-based membranes, which facilitate Proton conductivity in the temperature range of 120−200 °C. However, when leached out of the membrane by water produced during operation, H3PO4 adsorbs on the Pt catalyst surface, blocking the active sites and hindering the oxygen reduction reaction (ORR).
The reduction of H3PO4 to H3PO3, which occurs at the anode due to a combination of a low potential and the presence of gaseous H2, has been investigated as an additional important contributing factor to the observed poisoning effect. H3PO3 has an affinity toward adsorption on Pt surfaces even greater than that of H2PO4 −. In this work, we investigated the poisoning effect of both H3PO3 and H3PO4 using a half-cell setup with a gas diffusion electrode under ambient conditions. By means of in situ X-ray absorption spectroscopy, it was possible to follow the signature of different species adsorbed on the Pt nanoparticle catalyst (H, O, H2PO4 −, and H3PO3) at different potentials under ORR conditions in various electrolytes (HClO4, H3PO4, and H3PO3). It was found that H3PO3 adsorbs in a pyramidal configuration P(OH)3 through a Pt−P bond. The competition between H3PO4 and H3PO3 adsorption was studied, which should allow for a better understanding of the catalyst poisoning mechanism and thus assist in the development of strategies to mitigate this phenomenon in the future by minimizing H3PO3 generation by, for example, improved catalyst design or adapted operation conditions or changes in the electrolyte composition.
KW - H3PO4 life cycle
KW - XAS
KW - In situ coupling
KW - High-temperature fuel cells
KW - H3PO3,
KW - Δμ XANES
PY - 2022
DO - https://doi.org/10.1021/acscatal.2c02630
SN - 2155-5435
VL - 12
IS - 18
SP - 11472
EP - 11484
PB - American Chemical Society (ACS)
AN - OPUS4-64733
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 - Smekhova, A.
A1 - Kuzmin, A.
A1 - Siemensmeyer, K.
A1 - Luo, C.
A1 - Chen, K.
A1 - Radu, F.
A1 - Weschke, E.
A1 - Reinholz, Uwe
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Yusenko, Kirill
T1 - Al-driven peculiarities of local coordination and magnetic properties in single-phase Alx-CrFeCoNi high-entropy alloys
N2 - Modern design of superior multi-functional alloys composed of several principal components requires in-depth studies of their local structure for developing desired macroscopic properties. Herein, peculiarities of atomic arrangements on the local scale and electronic states of constituent elements in the single-phase face-centered cubic (fcc)- and body-centered cubic (bcc)-structured high-entropy Alx-CrFeCoNi alloys (x = 0.3 and 3, respectively) are explored by element-specific X-ray absorption spectroscopy in hard and soft X-ray energy ranges. Simulations based on the reverse Monte Carlo approach allow to perform a simultaneous fit of extended X-ray absorption fine structure spectra recorded at K absorption edges of each 3d constituent and to reconstruct the local environment within the first coordination shells of absorbers with high precision. The revealed unimodal and bimodal distributions of all five elements are in agreement with structure-dependent magnetic properties of studied alloys probed by magnetometry. A degree of surface atoms oxidation uncovered by soft X-rays suggests different kinetics of oxide formation for each type of constituents and has to be taken into account. X-ray magnetic circular dichroism technique employed at L2,3 absorption edges of transition metals demonstrates reduced magnetic moments of 3d metal constituents in the sub-Surface region of in situ cleaned fcc-structured Al0.3-CrFeCoNi compared to their bulk values. Extended to nanostructured versions of multicomponent alloys, such studies would bring new insights related to effects of high entropy mixing on low dimensions.
KW - X-ray magnetic circular dichroism (XMCD)
KW - High-entropy alloys
KW - Reverse Monte Carlo
KW - Magnetism
KW - Element-specific spectroscopy
KW - Extended X-ray absorption fine structure (EXAFS)
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530668
DO - https://doi.org/10.1007/s12274-021-3704-5
SN - 1998-0124
VL - 15
IS - 6
SP - 4845
EP - 4858
PB - Springer
AN - OPUS4-53066
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 - JOUR
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - Recent developments of X-ray absorption spectroscopy as analytical tool for biological and biomedical applications
N2 - X-ray absorption spectroscopy (XAS), in its various modalities, has gained exponential attention and applicability in the field of biological and biomedical systems. Particularly in this field, challenges like low concentration of analyte or proneness to radiation damage have certainly settle the basis for further analytical developments, when using X-ray based methods. Low concentration calls for higher sensitivity—by increasing the detection limits (DL); while susceptibility for radiation damage requires shorter measurement times and/or cryogenic sample environment possibilities. This manuscript reviews the latest analytical possibilities that make XAS more and more adequate to investigate biological or biomedical systems in the last 5 years.
KW - Biological & biomedical applications
KW - TXRF-XAS
KW - HERFD-XAS
KW - RXES
KW - Quick-XAS
KW - Dispersive-XAS
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531206
DO - https://doi.org/10.1002/xrs.3254
SN - 0049-8246
VL - 51
IS - 3
SP - 1
EP - 10
PB - John Wiley & Sons Ltd
AN - OPUS4-53120
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Peters, Stefan
A1 - Bartling, Stephan
A1 - Parlinska-Wojtan, Magdalena
A1 - Wotzka, Alexander
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Wohlrab, Sebastian
A1 - Abdel-Mageed, Ali M.
T1 - Stabilization of intermediate Mo oxidation states by Nb doping enhancing methane aromatization on Mo/HZSM-5 catalysts
N2 - The dehydroaromatization of methane is a promising process to produce aromatics and ultra-pure hydrogen. Increased yields and stability of Mo/HZSM-5 against irreversible deactivation were achieved via a redox interaction by doping with otherwise inert Nb.
KW - General Materials Science
KW - Sustainability and the Environment
KW - General Chemistry
KW - Renewable Energy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597670
DO - https://doi.org/10.1039/D3TA07532J
SN - 2050-7488
SP - 1
EP - 16
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59767
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Smekhova, Alevtina
A1 - Gaertner, Daniel
A1 - Kuzmin, Alexei
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Schuck, Goetz
A1 - Zizak, Ivo
A1 - Wilde, Gerhard
A1 - Yusenko, Kirill
A1 - Divinski, Sergiy
T1 - Anomalies in the short-range local environment and atomic diffusion in single crystalline equiatomic CrMnFeCoNi high-entropy alloy
N2 - AbstractMulti-edge extended X-ray absorption fine structure (EXAFS) spectroscopy combined with reverse Monte Carlo (RMC) simulations was used to probe the details of element-specific local coordinations and component-dependent structure relaxations in single crystalline equiatomic CrMnFeCoNi high-entropy alloy as a function of the annealing temperature. Two representative states, namely a high-temperature state, created by annealing at 1373 K, and a low-temperature state, produced by long-term annealing at 993 K, were compared in detail. Specific features identified in atomic configurations of particular principal components indicate variations in the local environment distortions connected to different degrees of compositional disorder at the chosen representative temperatures. The detected changes provide new atomistic insights and correlate with the existence of kinks previously observed in the Arrhenius dependencies of component diffusion rates in the CrMnFeCoNi high-entropy alloy.
KW - Electrical and Electronic Engineering
KW - General Materials Science
KW - Condensed Matter Physics
KW - Atomic and Molecular Physics, and Optics
KW - CCMat
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597687
DO - https://doi.org/10.1007/s12274-024-6443-6
SN - 1998-0124
VL - 17
IS - 6
SP - 5336
EP - 5348
PB - Springer Science and Business Media LLC
AN - OPUS4-59768
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -