TY - CONF
A1 - Yusenko, Kirill
A1 - Emmerling, Franziska
A1 - de Oliveira Guilherme Buzanich, Ana
T1 - X-Ray absorption spectroscopy to study multicomponent materials
N2 - Detailed study of multicomponent systems in solid-state as well as in solution using X-ray diffraction and X-ray spectroscopy is one of the most common topics in modern materials chemistry. 5-6 component high-entropy alloys such as fcc- and bcc-structured AlxCoCrFeNi and fluorescent nanoparticles based on fluorite-structured SrF2 doped by rare-earth metals in organic solutions have high complexity and their local structure cannot be resolved using only diffraction. X-ray absorption spectroscopy should be applied to understand peculiarities in their local structure and make a link between structure on short and long ranges and their macroscopic properties. Here, based on two representativee examples, we discuss how a combination of several X-ray absorption edges might give new insights into complex materials.
T2 - Virtual meeting of the African Light Source
CY - Online meeting
DA - 15.11.2021
KW - EXAFS
KW - Synchrotron studies
PY - 2021
AN - OPUS4-54014
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Yusenko, Kirill
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
T1 - Studies of high-entropy alloys using x-ray absorption fine structure at the bamline
N2 - BAM line is multipurpose high-energy beamline. To extend studies of multicomponent alloys using EXAFS we perform own research and user experiments requiring multiedge spectroscopy, high-temperature and chemically aggressive sample environments. Our study of multicomponent alloys and high-entropy alloys open new perspectives in understanding their reactivity, corrosion, phase transformations and local ordering.
T2 - SPP2006: large scale facilities
CY - Online meeting
DA - 02.11.2021
KW - Synchrotron studies
KW - High-entropy alloys
KW - EXAFS
PY - 2021
AN - OPUS4-54016
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Morcillo, Dalia
A1 - Oelze, Marcus
A1 - Seena Prem, Pranav
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Emmerling, Franziska
A1 - Recknagel, Sebastian
A1 - Panne, Ulrich
A1 - Abad Andrade, Carlos Enrique
T1 - Lithium isotope fractionation as an early indicator of degradation mechanisms in lithium-ion batteries
N2 - Aging in lithium-ion batteries (LIBs) degrades performance and hinders sustainability, demanding advanced diagnostics for early failure prediction. We investigate lithium isotope fractionation (LIF) as an innovative probe of degradation in lithium cobalt oxide (LCO) coin cells aged over 0−700 cycles. High-precision multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) quantified δ7Li variations across cell stages: non-cycled (0 cycles), newly formed (5 cycles), semi-aged (250 cycles), and fully aged (700 cycles). During early cycling (≤ 45 cycles), chemical processes drive 7Li enrichment at the anode (δ7Li vs LSVEC = +12 ‰) through solid electrolyte interphase (SEI) formation, while the cathode depletes in 7Li (δ7Li vs LSVEC = −0.7 ‰). Beyond 45 cycles, electric field-induced migration predominates, promoting 6Li intercalation into the anode and increasing the δ7Li of the cathode by 8.1 ‰. Mass balance verifies isotope conservation, attributing shifts to redistribution and trapping. Complementary electrochemical impedance spectroscopy (EIS) and X-ray absorption spectroscopy and diffraction confirm SEI expansion, cobalt oxidation, lattice shrinkage, and changes in electrode structure, corroborating LIF trends. Notably, a δ7Li inflection at approximately 270 cycles anticipates end-of-life by 70 cycles, surpassing traditional methods in sensitivity. LIF emerges as a predictive indicator of aging mechanisms, informing optimized designs for durable LIBs.
KW - Lithium isotope fractionation
KW - Lithium-ion batteries
KW - Degradation mechanisms
KW - LiCoO2 cathodes
KW - LCO
KW - Isotopic tracing
KW - Lithium isotopes
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650945
DO - https://doi.org/10.26434/chemrxiv-2025-16lvq
SP - 1
EP - 19
AN - OPUS4-65094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lutz, C.
A1 - Hampel, S.
A1 - Beuermann, S.
A1 - Turek, T.
A1 - Kunz, U.
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Fittschen, U. E. A.
T1 - Investigation on Vanadium Species Distribution in Nafion™ 117 after Cyclization in a Vanadium Redox Flow Battery
N2 - The vanadium redox flow battery (VRFB) is currently a potential candidate for stationary energy storage. A major challenge is the unintended vanadium transport through the separator, which results in a fade of capacity. To overcome this issue, it is necessary to understand the transport processes in the membrane on a more fundamental level. In this work, the vanadium species distribution in Nafion™ 117 after cyclization was investigated. Two membranes, one from a charged VRFB and another from a discharged VRFB, were analyzed using ultraviolet–visible spectroscopy (UV/VIS) and X-ray absorption near edge structure spectroscopy (XANES). Little difference between the two membranes was recognizable according to the UV/VIS results. In comparison, the XANES results showed that the membrane from the charged VRFB contains more V3+ than VO2+, whereas for the discharged case, more VO2+ is present in the membrane.
KW - Synchrotron
KW - BAMline
KW - XANES
KW - Vanadium redox flow battery
PY - 2021
VL - 64
SP - 1
EP - 8
AN - OPUS4-54144
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - INPR
A1 - Liu, Yanchen
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Alippi, Paola
A1 - Lee, Kug-Seung
A1 - Jeon, Taeyeol
A1 - Weißer, Kilian
A1 - Karlsen, Martin A.
A1 - Russo, Patrícia A.
A1 - Pinna, Nicola
T1 - FeNb2O6 as a high-performance anode for sodium-ion batteries enabled by structural amorphization coupled with NbO6 local ordering.
N2 - Pseudocapacitance-type transition metal oxides have been extensively investigated as anodes materials for lithium-ion batteries. Currently, they are also emerging as promising anodes for sodium-ion batteries due to their low volume change and safety. However, the potential electrochemical performance in sodium energy storage is not fully achieved, primarily due to the larger radius of the Na+-ions. Here, we report for the first time an iron niobate with columbite structure as a high-performance sodium storage anode. The presence of iron in the structure is vital to trigger the loss of long-range order through disorder of the FeO6 octahedra local structure, subsequently allowing reversible Na storage in an amorphous phase. Simultaneously, the formation of short-range ordered zigzag-chain structures within the NbO6 planes creates a “skeleton” that offers abundant active sites for pseudocapacitive ion storage and enhanced ion diffusion pathways. These characteristics of FeNb2O6 make it an effective intercalation host, offering high capacity along with fast Na+ insertion and extraction, as demonstrated through operando and ex-situ characterizations. It leads to an applicable reversible capacity ( 300 mAh g-1) with a favorable average voltage of ca. 0.6 V and excellent rate capability (180.4 mAh g-1 at a current density of 2 A g-1). This study provides insights into the development of intrinsically active transition metal oxides for Na+-ion intercalation.
KW - XAS
KW - Sodium-Ion-Batteries
KW - In-situ
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631159
DO - https://doi.org/10.26434/chemrxiv-2025-2gn7z
SP - 1
EP - 51
PB - American Chemical Society (ACS)
AN - OPUS4-63115
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 - Emmerling, Franziska
A1 - Hampel, S.
A1 - Fittschen, UEA
A1 - Streli, C.
A1 - Radtke, Martin
T1 - Reconstruction for coded aperture full-field x-ray fluorescence imaging
N2 - X-ray fluorescence imaging is a well-established tool in materials characterization. In this work, we present the adaption of coded aperture imaging to full-field X-ray fluorescence imaging at the synchrotron. Coded aperture imaging has its origins in astrophysics, and has several advantages: Coded apertures are relatively easy to fabricate, achromatic, allow a high photon throughput, and high angular acceptance. Coded aperture imaging is a two-step-process, consisting of the measurement process and a reconstruction step. Different programs have been written, for the raytracing/forward projection and the reconstruction. Experiments with coded aperture in combination with a Color X-ray Camera and an energy-dispersive area detector, have been conducted at the BAMline. Measured samples were successfully reconstructed, and gave a 9.1-fold increase in count rate compared to a polycapillary optic.
KW - Synchrotron
KW - BAMline
KW - Coded Aperture
PY - 2022
SN - 1097-0002
VL - 65
SP - 57
EP - 70
PB - Cambridge University Press
CY - Cambridge
AN - OPUS4-56350
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 - CONF
A1 - Dietzmann, Simon
A1 - Mehmood, Asad
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Emmerling, Franziska
A1 - Fellinger, Tim-Patrick
A1 - Thomas, A.
T1 - Characterization of Solid-State Complexes by XAS
N2 - Atomically dispersed metal-nitrogen doped carbons (M-N-C) are
promising catalysts for the activation of small molecules such as O2
and CO2. These single atom catalysts (SAC) operate at the interface
between homogenous and heterogenous catalysts. Currently, many
examples of M-N-C are known with good oxygen reduction reaction
activity but lacking a controlled synthesis of the specific active sites of
the precatalyst. Recently, our group facilitated the synthesis of pure
pyrrolic M-N4 sites using Zn ions as imprinters.[1] These amorphous
materials obtained by active site imprinting method are characterized
at the BAMline (Bessy II) by X-ray absorption spectroscopy (XAS).
In-situ/operando measurements will be crucial in future work for a
better understanding of the dynamic changes of the active site.
T2 - InSynX Workshop 2023
CY - Sao Paulo, Brazil
DA - 06.03.2023
KW - Solid-State Complexes
PY - 2023
AN - OPUS4-58933
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Reinholz, Uwe
A1 - Riesemeier, Heinrich
A1 - Emmerling, Franziska
T1 - Time- & spatial-resolved X-ray absorption fine structure (XAFS) spectroscopy in a single-shot – new analytical possibilities for in situ material characterization
N2 - A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator. 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 either an energy-sensitive area detector, the so-called color X-ray camera, or by an area-sensitive detector based on a CCD camera, in θ-2θ geometry. The first tests were performed with thin metal foils and some iron oxide mixtures. A time resolution of lower than 1 s together with a spatial resolution in one dimension of at least 50 µm is achieved.
KW - Time resolution
KW - Single-shot XAFS
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370892
DO - https://doi.org/10.1107/S1600577516003969
SN - 1600-5775
IS - 23
SP - 769
EP - 776
PB - International Union of Crystallography
CY - Chester, UK
AN - OPUS4-37089
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Radtke, Martin
A1 - Reinholz, Uwe
A1 - Riesemeier, Heinrich
A1 - Emmerling, Franziska
ED - de Oliveira Guilherme Buzanich, Ana
T1 - Time- and spatial-resolved X-ray absorption fine structure (XAFS) spectroscopy in a single-shot: new analytical possibilities for in situ material characterization
N2 - A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator. 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 either an energy-sensitive area detector, the so-called color X-ray camera, or by an area-sensitive detector based on a CCD camera, in θ-2θ geometry. The first tests were performed with thin metal foils and some iron oxide mixtures. A time resolution of lower than 1 s together with a spatial resolution in one dimension of at least 50 µm is achieved.
KW - Single-shot XAFS
KW - Time resolution
KW - Spatial resolution
KW - Divergent XAFS
PY - 2016
DO - https://doi.org/10.1107/S1600577516003969
SN - 1600-5775
VL - 23
SP - 769
EP - 776
PB - International Union of Crystallography
AN - OPUS4-38370
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -