TY - JOUR A1 - Durlo Tambara, Luís Urbano A1 - Nikoonasab, Ali A1 - Radtke, Martin A1 - de Oliveira Guilherme Buzanich, Ana A1 - Gluth, Gregor T1 - Determination of the oxidation depths of ground granulated blast furnace slag-containing cement pastes using Mn K-edge X-ray absorption near-edge structure spectroscopy N2 - The redox potential of the pore solution of hardened cements containing ground granulated blast furnace slag (GGBFS) affects reinforcement corrosion and immobilization of radioactive waste. Here, Mn K-edge X-ray absorption near-edge structure (XANES) spectroscopy was applied to determine the depth profile of the oxidation state of manganese in hardened GGBFS-containing cement pastes. Manganese was oxidized in the outer regions of some of the pastes, but the depth to which this occurred was not identical with the ‘blue-green/white color change front’, usually interpreted as indicating oxidation of sulfur species. For CEM III/B, the color change of the material was gradual and thus unsuitable for a precise determination of the oxidation depth, while for the alkali-activated slag, a distinct color change front was found, but full oxidation of manganese and sulfur had not occurred in the brighter region. Mn K-edge XANES spectroscopy is thus a more reliable method than the determination of the visual color change front to follow the ingress of the oxidation front. KW - Manganese KW - Oxidation KW - Sulfide KW - Alkali-activated materials KW - Redox conditions PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651469 DO - https://doi.org/10.1111/jace.70445 SN - 0002-7820 SN - 1551-2916 VL - 109 IS - 1 SP - 1 EP - 11 PB - Wiley CY - Oxford AN - OPUS4-65146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pavlidis, Sotirios A1 - Fischer, Eric W. A1 - Opis-Basilio, Amanda A1 - Bera, Ayan A1 - Guilherme Buzanich, Ana A1 - Álvarez-Sánchez, María A1 - Wittek, Severin A1 - Emmerling, Franziska A1 - Ray, Kallol A1 - Roemelt, Michael A1 - Abbenseth, Josh T1 - Ambiphilic Reactivity and Switchable Methyl Transfer at a T-Shaped Bi(NNN) Complex Enabled by a Redox-Active Pincer Ligand N2 - We report the transition-metal-like reactivity of a geometrically constrained, ambiphilic bismuth(III) trisamide. Planarization of the Bi(III) center unlocks Bi−C bond formation when reacted with mild electrophiles (alkyl iodides and triflates) accompanied by two-electron oxidation of the utilized NNN pincer nligand. The preservation of the bismuth oxidation state is confirmed by single-crystal X-ray diffraction and X-ray absorption spectroscopy and corroborated by theoretical calculations. Sequential reduction of the oxidized ligand framework alters the reactivity of a generated Bi−Me unit, enabling controlled access to methyl cation, radical, and anion equivalents. The full [Bi(Me)(NNN)]+/•/− redox series was comprehensively characterized using NMR and EPR spectroscopy as well as spectro-electrochemistry. This work represents the first example of ligand-assisted, redox-neutral C−X bond splitting at bismuth, establishing a new paradigm for synthetic bismuth chemistry. KW - Pincer ligand KW - XAS KW - Redox PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654948 DO - https://doi.org/10.1021/jacs.5c18955 SN - 0002-7863 VL - 148 IS - 2 SP - 2683 EP - 2692 PB - American Chemical Society (ACS) AN - OPUS4-65494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hickel, Tilmann A1 - Waske, Anja A1 - Tehranchi, Ali A1 - Bhattacharya, Biswajit A1 - Stawski, Tomasz M. A1 - Fellinger, Tim-Patrick A1 - Mehmood, Asad A1 - Witt, Julia A1 - Ozcan, Ozlem A1 - Guilherme Buzanich, Ana A1 - Kumar, Sourabh A1 - Mishra, Rajesh Kumar A1 - Holzer, Marco A1 - Stucchi de Camargo, Andrea Simone A1 - Agudo Jácome, Leonardo A1 - Manzoni, Anna A1 - Fantin, Andrea A1 - John, Elisabeth A1 - Hodoroaba, Vasile-Dan A1 - Bührig, Sophia A1 - Murugan, Jegatheesan A1 - Marschall, Niklas A1 - George, Janine A1 - Darvishi Kamachali, Reza A1 - Maaß, Robert A1 - Emmerling, Franziska T1 - Chemically complex materials enable sustainable high-performance materials N2 - Chemically complex materials (CCMats) 􀀀 including high-entropy alloys, oxides, and related multi-principal element systems 􀀀 offer a paradigm shift in materials design by leveraging chemical diversity to simultaneously optimize functional, structural, and sustainability criteria. The vastness of the compositional and structural space in CCMats propels the field into an expanding exploratory state. To reconcile functional and structural performance across this immense parameter space remains an open challenge. This Perspective evaluates the opportunities and challenges associated with harnessing chemical complexity across a broad spectrum of applications, such as hydrogen storage, ionic conductors, catalysis, magnetics, dielectrics, semiconductors, optical materials, and multifunctional structural systems. It is delineated how three central design strategies: targeted substitution (SUB), defect engineering (DEF), and diversity management (DIV) enable the reconciliation of high functional performance with long-term structural stability and environmental responsibility. Advances in computational thermodynamics, microstructure simulations, machine learning, and multimodal characterization are accelerating the exploration and optimization of CCMats, while robust data infrastructures and automated synthesis workflows are emerging as essential tools for navigating their complex compositional space. By fostering cross-disciplinary knowledge transfer and embracing data-driven design, CCMats are poised to deliver next-generation materials solutions that address urgent technological, energy, and environmental demands. KW - Chemically complex materials KW - Structural stability KW - Functional performance KW - Design strategies KW - Sustainability PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655598 UR - https://www.sciencedirect.com/science/article/pii/S1359028626000033?via%3Dihub DO - https://doi.org/10.1016/j.cossms.2026.101256 SN - 1359-0286 VL - 42 SP - 1 EP - 26 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-65559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - Bridging Structure and Electronic State: Real-time XES–XRD Fusion for Functional Alloys N2 - We present a unified X-ray Emission Spectroscopy (XES) and X-ray Diffraction (XRD) approach for real-time, in situ characterization of materials, demonstrated on Co₂FeSi Heusler alloys under varied heat treatments. The combination of XES and XRD is particularly well-suited to Heusler alloys, where subtle changes in atomic ordering and electronic structure (e.g. site occupancy, hybridization, and spin state) are tightly interdependent and critical for their magnetic and transport properties. In addition, this method enables more efficient materials design by reducing experimental iterations through comprehensive structural and electronic analysis. Developed at the mySpot beamline at BESSY-II, the platform integrates (a) digital twin-based experiment planning, (b) open-source XES spectral simulations, (c) an optimized single-shot, two-element XES setup with sub-pixel resolution for enhanced energy precision, and (d) result-driven beamtime utilization. With an unprecedented synchronized XES-XRD platform, we aim to shed light on how diffusion-controlled processes in Heusler alloys and double perovskites at elevated temperatures establish the formation of specific phases with distinct structure types in real time. This, in turn, strongly impacts the functional properties of the materials under scrutiny. T2 - XLIV Colloquium Spectroscopicum Internationale CY - Ulm, Germany DA - 27.07.2025 KW - Multimodal KW - X-ray spectroscopy KW - X-ray diffraction KW - Functional alloys PY - 2025 AN - OPUS4-63991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cakir, Cafer Tufan A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - A Digital Twin Workflow for Optimizing X-ray Emission Spectroscopy (XES) Parameters in Material Science N2 - In this contribution, I present a digital twin-based workflow designed to optimize experimental parameters in X-ray emission spectroscopy (XES), with a focus on reproducibility, data integration, and alignment with FAIR (Findable, Accessible, Interoperable, Reusable) principles in materials science and engineering (MSE). The developed pipeline begins with automated retrieval of crystallographic information from the Materials Project database based on a given sample composition. This structural data is then used to simulate the corresponding XES spectra using FDMNES, allowing for accurate prediction of element-specific emission lines. The simulated emission lines are fed into an X-ray tracing (XRT) module, which builds a virtual replica of the experimental setup. This digital twin environment enables predictive modeling of spectrometer performance based on geometric configurations. The optimization focuses on two key parameters: the choice of the analyzing crystal and the distance between the sample and crystal (which also defines the crystal–detector distance due to Bragg condition constraints). An active learning algorithm is employed to iteratively adjust these parameters in order to achieve a desired energy-per-pixel (E/pixel) resolution with minimal intensity loss, enabling efficient, data-driven experimental planning. By integrating data-driven simulations with real-time optimization strategies, this workflow supports efficient experiment planning while minimizing resource consumption and human error. Furthermore, all stages of the process—from data collection and simulation to optimization and visualization—are structured to ensure traceability and interoperability, facilitating future reuse and collaborative research. I hope this contribution aligns well with the topic “Workflows for FAIR MSE Data” and offers a concrete example of how digital twins can be harnessed to improve the design, execution, and documentation of spectroscopy experiments in the MSE domain. T2 - Opportunities and Challenges of FAIR Data at Photon and Neutron Facilities CY - Bad Honnef, Germany DA - 12.10.2025 KW - Digital-Twin KW - XES KW - Optimization KW - Machine Learning PY - 2025 AN - OPUS4-64676 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 - CONF A1 - de Oliveira Guilherme Buzanich, Ana T1 - The versatility of XAS@BAM for real-time in situ electrocatalysis in collaborative materials research N2 - With the global push toward sustainable energy technologies, the development of efficient and durable electrocatalysts has become a research priority. Real-time in situ studies are essential to understand the dynamic behavior of catalysts under operational conditions. X-ray absorption spectroscopy (XAS) offers a unique, element-specific probe of electronic and structural changes at the active sites of electrocatalysts during electrochemical reactions. At BAM, collaborative research efforts leverage the advanced capabilities of the BAMline at the Berlin Synchrotron BESSY-II to study electrocatalytic materials under realistic working conditions. As a dedicated materials research beamline, the BAMline enables in situ and operando XAS across different time and length scales, making it ideally suited for monitoring catalytic transformations in real time. This presentation highlights the analytical strengths and sample environments developed for electrochemical cells at BAM, showcasing their application to electrocatalysis for energy conversion (e.g., water splitting, CO₂ reduction). Emphasis will be placed on how these insights contribute to the rational design and real-time optimization of functional materials for a sustainable energy future. T2 - MATSUS Konferenz CY - Valencia, Spanien DA - 20.10.2025 KW - Operando KW - XAS KW - In situ KW - Electrocatalysis PY - 2025 AN - OPUS4-64493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yun, Tae Gyu A1 - Chen, Boqiang A1 - Wells, Sarah A1 - Lim, Younghwan A1 - Kim, Jun Seop A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Waegele, Matthias M. A1 - Risch, Marcel A1 - Grimaud, Alexis ED - de Oliveira Guilherme Buzanich, Ana T1 - Extrinsic and Intrinsic Factors Governing the Electrochemical Oxidation of Propylene in Aqueous Solutions N2 - The electrochemical synthesis of commoditychemicals such as epoxides and glycols offers a sustainablealternative to conventional methods that involve hazardouschemicals. Efforts to improve the yield and selectivity of propyleneoxidation using Pd-based catalysts have been shown to be highlysensitive to applied potential, pH, and electrochemical cell design.Record efficiencies and yields were obtained by substitution ofPdO by 4d or 5d transition metals, including Pt, with thus far littlerationale regarding the origin for the improvement. Throughelectrochemical analysis, scanning transmission electron micros-copy, X-ray absorption spectroscopy, and surface-enhanced infraredabsorption spectroscopy, we investigated the mechanism ofpropylene oxidation on Pd-based catalysts. We demonstrate thatadsorbates forming on PdO, where Pd adopts a square-planar coordination [PdO4], differ from that forming on the surface ofoxidized metallic Pd catalysts with an oxo intermediate mediating propylene oxidation on PdO. We further show that Pt substitutionin PdO does not modify this oxo intermediate. Varying pH, we found that the onset for propylene oxidation is pH independent,indicating a potential-determining step where the proton is not involved in and similar reaction pathway in acidic and near-neutralconditions. Finally, our work undoubtedly demonstrates that high Faradaic efficiency toward propylene glycol and propylene oxideformation, such as those previously reported in the literature, can be achieved by means of electrode engineering and mastery ofmass transport and local pH. Notably, we achieved ≈100% faradaic efficiency for propylene glycol at 1.7 V vs RHE in acidic mediausing a Pt-substituted PdO catalyst loaded onto a gas diffusion electrode. KW - XAS KW - Electrochemistry KW - Popylene oxidation KW - 4d metals PY - 2025 DO - https://doi.org/10.1021/jacs.5c02585 SN - 0002-7863 VL - 147 IS - 14 SP - 12318 EP - 12330 PB - American Chemical Society (ACS) AN - OPUS4-63112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liu, Yanchen A1 - de Oliveira Guilherme Buzanich, Ana A1 - Montoro, Luciano A. A1 - Liu, Hao A1 - Liu, Ye A1 - Emmerling, Franziska A1 - Russo, Patrícia A. A1 - Pinna, Nicola T1 - A partially disordered crystallographic shear block structure as fast-charging negative electrode material for lithium-ion batteries N2 - A well-ordered crystalline structure is crucial in battery electrodes, as the dimensionality and connectivity of the interstitial sites inherently influence Li+ ions diffusion kinetics. Niobium tungsten oxides block structures, composed of ReO3-type blocks of specific sizes with well-defined metal sites, are promising fast-charging negative electrode materials. Structural disorder is generally detrimental to conductivity or ion transport. However, here, we report an anomalous partially disordered Nb12WO33 structure that significantly enhances Li-ion storage performance compared to the known monoclinic Nb12WO33 phase. The partially disordered phase consists of corner-shared NbO6 octahedra blocks of varied sizes, including 5×4, 4×4, and 4×3, with a disordered arrangement of distorted WO4 tetrahedra at the corners of the blocks. This structural arrangement is robust during lithiation/delithiation, exhibiting minor local structure changes during cycling. It enables accelerated Li-ion migration, resulting in promising fast-charging performance, namely, 62.5 % and 44.7 % capacity retention at 20 C and 80 C, respectively. This study highlights the benefits of introducing disorder into niobium tungsten oxide shear structures, through the establishment of clear structure-performance correlations, offering guidelines for designing materials with targeted properties. KW - Lithium ion batteries KW - Oxides KW - XANES KW - XRD PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637994 DO - https://doi.org/10.1038/s41467-025-61646-9 SN - 2041-1723 VL - 16 IS - 1 SP - 1 EP - 15 PB - Springer Science and Business Media LLC AN - OPUS4-63799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pessanha, Sofia A1 - Fortes, António A1 - Lopes, Marta B. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Ortega-Feliu, Inés A1 - Respaldiza, Miguel A. A1 - Gomez Tubio, Blanca A1 - Makarova, Anna A1 - Smirnov, Dmitry A1 - Kumar, Sourabh A1 - Mata, António A1 - Silveira, João T1 - Multi-technique computational assessment of fluoride uptake in enamel using PIGE, NEXAFS, and Raman spectroscopy N2 - This study explores F incorporation in enamel via PIGE, NEXAFS, and Raman spectroscopy, integrating experimental/simulated spectra. Machine Learning boosts data interpretation, offering key insights into F delivery for clinical application. KW - Simulations KW - Enamel KW - Fuorine KW - NEXAFS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631138 DO - https://doi.org/10.1039/D5TB00213C SN - 2050-750X SP - 1 EP - 10 PB - Royal Society of Chemistry (RSC) AN - OPUS4-63113 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -