TY - JOUR A1 - Sreekala, L. A1 - Dey, P. A1 - Hickel, Tilmann A1 - Neugebauer, J. T1 - Unveiling nonmonotonic chemical trends in the solubility of H in complex Fe-Cr-Mn carbides by means of ab initio based approaches N2 - The microstructure of advanced high-strength steels often shows a sensitive dependence on alloying. For example, adding Cr to improve the corrosion resistance of medium-Mn steels also enhances the precipitation of carbides. The current study focuses on the behavior of H in such complex multicomponent carbides by employing different methodological strategies. We systematically analyze the impact of Cr, Mn, and Fe using density functional theory (DFT) for two prototype precipitate phases, M3C and M23C6, where M represents the metal sublattice. Our results show that the addition of these alloying elements yields strong nonmonotonic chemical trends for the H solubility. We identify magnetovolume effects as the origin for this behavior, which depend on the considered system, the sites occupied by H, and short- vs long-range interactions between H and the alloying elements. We further show that the H solubility is directly correlated with the occupation of its nearest-neighbor shells by Cr and Mn. Based on these insights, DFT data from H containing binary-metal carbides are used to design a ridge regression based model that predicts the solubility of H in the ternary-metal carbides (Fe-Cr-Mn-C). KW - Hydrogen KW - High-strength steel KW - Carbide KW - Ab initio KW - Complexity PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542271 DO - https://doi.org/10.1103/PhysRevMaterials.6.014403 SN - 2475-9953 VL - 6 IS - 1 SP - 1 EP - 14 PB - American Physical Society (APS) CY - College Park, MD AN - OPUS4-54227 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sprachmann, J. A1 - Wachsmuth, T. A1 - Bhosale, M. A1 - Burmeister, D. A1 - Smales, Glen Jacob A1 - Schmidt, M. A1 - Kochovski, Z. A1 - Grabicki, N. A1 - Wessling, R. A1 - List-Kratochvil, E. J. W. A1 - Esser, B. A1 - Dumele, O. T1 - Antiaromatic Covalent Organic Frameworks Based on Dibenzopentalenes N2 - Despite their inherent instability, 4n π systems have recently received significant attention due to their unique optical and electronic properties. In dibenzopentalene (DBP), benzanellation stabilizes the highly antiaromatic pentalene core, without compromising its amphoteric redox behavior or small HOMO−LUMO energy gap. However, incorporating such molecules in organic devices as discrete small molecules or amorphous polymers can limit the performance (e.g., due to solubility in the battery electrolyte solution or low internal surface area). Covalent organic frameworks (COFs), on the contrary, are highly ordered, porous, and crystalline materials that can provide a platform to align molecules with specific properties in a well-defined, ordered environment. We synthesized the first antiaromatic framework materials and obtained a series of three highly crystalline and porous COFs based on DBP. Potential applications of such antiaromatic bulk materials were explored: COF films show a conductivity of 4 × 10−8 S cm−1 upon doping and exhibit photoconductivity upon irradiation with visible light. Application as positive electrode materials in Li-organic batteries demonstrates a significant enhancement of performance when the antiaromaticity of the DBP unit in the COF is exploited in its redox activity with a discharge capacity of 26 mA h g−1 at a potential of 3.9 V vs. Li/Li+ . This work showcases antiaromaticity as a new design principle for functional framework materials. KW - SAXS KW - MOUSE KW - Covalent Organic Frameworks KW - Batteries PY - 2023 DO - https://doi.org/10.1021/jacs.2c10501 SP - 1 EP - 12 PB - ACS Publications AN - OPUS4-56958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sprachmann, J. A1 - Grabicki, N. A1 - Möckel, Anna A1 - Maltitz, J. A1 - del Refugio Monroy Gómez, J. A1 - Smales, Glen Jacob A1 - Dumele, O. T1 - Substituted Benzophenone Imines for COF Synthesis via Formal Transimination N2 - Covalent organic frameworks (COFs) are a prominent class of organic materials constructed from versatile building blocks via reversible reactions. The quality of imine-linked COFs can be improved by using amine monomers protected with benzophenone forming benzophenone imines. Here, we present a study on substituted benzophenones in COF synthesis via formal transimination. 12 para-substituted N-aryl benzophenone imines, with a range of electron-rich to electron-poor substituents, were prepared and their hydrolysis kinetics were studied spectroscopically. All substituted benzophenone imines can be employed in COF synthesis and lead to COFs with high crystallinity and high porosity. The substituents act innocent to COF formation as the substituted benzophenones are cleaved off. Imines can be tailored to their synthetic demands and utilized in COF formation. This concept can make access to previously unattainable, synthetically complex COF monomers feasible. KW - Materials Chemistry KW - Metals and Alloys KW - Surfaces, Coatings and Films KW - General Chemistry KW - Ceramics and Composites KW - Electronic, Optical and Magnetic Materials KW - Catalysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586449 DO - https://doi.org/10.1039/D3CC03735E SN - 1359-7345 SP - 1 EP - 4 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Speight, Isaiah R. A1 - Ardila-Fierro, Karen J. A1 - Hernández, José G. A1 - Emmerling, Franziska A1 - Michalchuk, Adam A. L. A1 - García, Felipe A1 - Colacino, Evelina A1 - Mack, James T1 - Ball milling for mechanochemical reactions N2 - Mechanochemistry is an emerging field with the potential to pave the way for sustainable chemistry. Although the use of mechanical force to initiate chemical reactions has been recognized for millennia, it has often taken a backseat to thermal and photonic methods. Over the past 30 years, mechanochemistry has seen a resurgence of interest, attracting researchers across the globe. Despite its proven ability to address numerous challenges within the chemical community, mechanochemistry remains on the periphery. This Primer serves as a valuable guide for conducting mechanochemical reactions by ball milling, offering an overview of the processes, methods, tools and terminology necessary to embark on research in this field. It also highlights persistent hurdles such as equipment standardization, understanding the impact of new discoveries and the lack of predictability of reaction outcomes. The Primer’s focus is on how mechanochemical ball milling is used in various chemical transformations, distinguishing it from other forms of mechanochemistry discussed in the literature. With a promising future, this Primer serves as a gateway for those aspiring to contribute to the field’s advancement. KW - Mechanochemistry KW - Ball milling KW - Upscaling PY - 2025 DO - https://doi.org/10.1038/s43586-025-00401-2 SN - 2662-8449 VL - 5 IS - 1 SP - 1 EP - 18 PB - Springer Science and Business Media LLC AN - OPUS4-63447 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Spaltmann, Dirk T1 - Tribological performance of FS-laser-induced periodic surface structures on titanium alloy against different counter-body materials using a ZDDP lubricant additive N2 - In this study the so-called laser-induced periodic surface structures (LIPSS, ripples) were produced on titanium alloy (Ti6Al4V) surfaces upon scan processing in air by a Ti:sapphire femtosecond (fs) laser. The tribological performance of the resulting surfaces was qualified in linear reciprocating sliding tribological tests (RSTT) against balls made of different materials (100Cr6 steel/Al2O3/Si3N4) using different oil-based lubricants. The admixture of the additive 2-ethylhexylzinc-dithiophosphate (ZDDP) to a base oil containing only anti-oxidants and temperature stabilizers disclosed the synergy of the additive with the laser-oxidized nanostructures. This interplay between the laser-textured sample topography and the local chemistry in the tribological contact area reduces friction and wear. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Lubricant additives KW - Laser-induced periodic surface structures (LIPSS) KW - Wear KW - Friction PY - 2022 AN - OPUS4-55318 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Souza, B. A1 - Chauque, S. A1 - de Oliveira, P. A1 - Emmerling, Franziska A1 - Torresi, R. T1 - Mechanochemical optimization of ZIF-8/Carbon/S8 composites for lithium-sulfur batteries positive electrodes N2 - The application of lithium-sulfur (Li-S) batteries is still limited by their rapid capacity fading. The pulverization of the sulfur positive electrode after the lithiation and the consequence dissolution of long chain polysulfides in organic solvents lead to the shuttle effect. To address these issues, here we report the mechanochemical preparation of ZIF-8 (Zeolitic Imidazole Framework-8)-based composites as sulfur hosts for positive electrodes in Li-S batteries. We studied different methods for the incorporation of conductive carbon. Also, the replacement of Zn2+ metal centers by other bivalent metals (Cu2+, Co2+ and Ni2+), enabled the preparation of other ZIF-8-based materials. The positive electrode ZIF-8/C/S8 showed initial discharges of 772 mA h g−1 while the pristine one, ZIF-8/S8, displayed 502 mA h g−1. The enhanced performance of 54% for ZIF-8/C/S8 indicates that the direct mechanochemical synthesis of ZIF-8 with conductive carbon is beneficial at initials charge/discharge process in comparison to traditional slurry preparation (ZIF-8/S8). Also, the Li2S6 absorption tests shows 87% of discoloration with ZIF-8/C/S8, confirming the better polysulfides absorption. KW - Lithium-sulfur battery KW - Metal organic frameworks KW - ZIF-8 KW - Mechanochemistry PY - 2021 DO - https://doi.org/10.1016/j.jelechem.2021.115459 VL - 896 SP - 115459 PB - Elsevier B.V. AN - OPUS4-53542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sordello, F. A1 - Prozzi, M. A1 - Hodoroaba, Vasile-Dan A1 - Radnik, Jörg A1 - Pellegrino, F. T1 - Increasing the HER efficiency of photodeposited metal nanoparticles over TiO2 using controlled periodic illumination N2 - Although the use of noble metal catalysts can increase the efficiency of hydrogen evolution reaction, the process is still limited by the characteristics of the metal-hydrogen (M−H) bond, which can be too strong or too weak, depending on the metal employed. Studies revealed that the hydrogen affinity for the metal surface (i.e. H absorption/desorption) is regulated also by the potential at the metal nanoparticles. Through controlled periodic illumination (CPI) of a series of metal/TiO2 suspensions, here we demonstrated that an increase of the HER efficiency is possible for those photodeposited metals which have a Tafel slope below 125 mV. Two possible explanations are here reported, in both of them the M−H interaction and the metal covering level play a prominent role, which also depend on the prevailing HER mechanism (Volmer-Heyrovsky or Volmer-Tafel). KW - Controlled periodic illumination KW - Hydrogen evolution reaction KW - Titanium dioxide KW - Photoreforming KW - Volcano plot KW - Sabatier KW - Nanoparticles PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589875 DO - https://doi.org/10.1016/j.jcat.2023.115215 VL - 429 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-58987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Song, L. A1 - You, Yi A1 - Perdomo, R. A1 - Evans-Nguyen, T. T1 - Inexpensive Ultrasonic Nebulization Coupled with Direct Current Corona Discharge Ionization Mass Spectrometry for Liquid Samples and Its Fundamental Investigations N2 - The concept of direct mass-spectrometric analysis, especially exploited by ambient desorption/ionization (ADI) methods, provides numerous means for convenient sample analysis. While many simple and versatile ionization sources have been developed, challenges lay in achieving efficient sample introduction. In previous work, a sample introduction method employing direct current corona discharge (CD) coupled to a surface acoustic wave nebulization (SAWN) device enhanced sampling performance for both polar and nonpolar analytes by up to 4 orders of magnitude. In fact, the SAWN-CD method generated a multiply charged peptide ion signal comparable to that of conventional ESI. Unfortunately, the high cost of the SAWN devices themselves limits their accessibility. Herein, we report on an analogous implementation of CD with an inexpensive ultrasonic nebulizer (USN) on the basis of a commercial room humidifier demonstrating equivalent exemplary performance. We subsequently compare the two methods of SAWN-CD and USN-CD in a screening application of milk for the detection of two antibiotic drugs, ciprofloxacin and ampicillin. Finally, we further investigate the relative softness of these CD-coupled acoustic nebulization methods in comparison to that of ESI using a survival yield study of the thermometer ion nitrobenzylpyridinium. KW - Rapid Analysis KW - Ultrasonic Nebulization KW - Corona Discharge PY - 2020 DO - https://doi.org/10.1021/acs.analchem.0c00524 VL - 92 IS - 16 SP - 11072 PB - ACS Publication AN - OPUS4-51225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Somasundaram, S. K. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Krishnan, S. A1 - Senthilkumar, K. A1 - Joseyphus, R.J. T1 - New insights into pertinent Fe-complexes for the synthesis of iron via the instant polyol process N2 - Chemically synthesized iron is in demand for biomedical applications due to its large saturation magnetization compared to iron oxides. The polyol process, suitable for obtaining Co and Ni particles and their alloys, is laborious in synthesizing Fe. The reaction yields iron oxides, and the reaction pathway remains unexplored. This study shows that a vicinal polyol, such as 1,2-propanediol, is suitable for obtaining Fe rather than 1,3-propanediol owing to the formation of a reducible Fe intermediate complex. X-ray absorption spectroscopy analysis reveals the ferric octahedral geometry and tetrahedral geometry in the ferrous state of the reaction intermediates in 1,2-propanediol and 1,3-propanediol, respectively. The final product obtained using a vicinal polyol is Fe with a γ-Fe2O3 shell, while the terminal polyol is favourable for Fe3O4. The distinct Fe–Fe and Fe–O bond lengths suggest the presence of a carboxylate group and a terminal alkoxide ligand in the intermediate of 1,2-propanediol. A large Fe–Fe bond distance suggests diiron complexes with bidentate carboxylate bridges. Prominent high-spin and low-spin states indicate the possibility of transition, which favors the reduction of iron ions in the reaction using 1,2-propanediol. KW - XAS KW - Nanoparticle PY - 2023 DO - https://doi.org/10.1039/D3CP01969A SN - 1463-9076 VL - 25 IS - 33 SP - 21970 EP - 21980 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Hahn, Marc Benjamin A1 - Smiatek, J. T1 - Raman spectroscopic signature of ectoine conformations in bulk solution and crystalline state N2 - Recent crystallographic results revealed conformational changes of zwitterionic ectoine upon hydration. By means of confocal Raman spectroscopy and density functional theory calculations, we present a detailed study of this transformation process as part of a Fermi resonance analysis. The corresponding findings highlight that all resonant couplings are lifted upon exposure to water vapor as a consequence of molecular binding processes. The importance of the involved molecular groups for water binding and conformational changes upon hydration is discussed. Our approach further Shows that the underlying rapid process can be reversed by carbon dioxide saturated atmospheres. For the first time, we also confirm that the conformational state of ectoine in aqueous bulk solution coincides with crystalline ectoine in its dihydrate state, thereby highlighting the important role of a few bound water molecules. KW - Fermi resonance KW - Ectoine hydration KW - DFT calculations of Raman spectra KW - Position of carboxylate group PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509855 DO - https://doi.org/10.1002/cphc.202000457 SN - 1439-4235 SN - 1439-7641 VL - 21 IS - 17 SP - 1945 EP - 1950 PB - Wiley-VCH CY - Weinheim AN - OPUS4-50985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Cordsmeier, Leo A1 - Hallier, Dorothea C. A1 - Seitz, Harald A1 - Hahn, Marc Benjamin T1 - Interaction of a Dimeric Single-Stranded DNA-Binding Protein (G5P) with DNA Hairpins. A Molecular Beacon Study N2 - Gene-V protein (G5P/GVP) is a single-stranded (ss)DNA-binding protein (SBP) of bacteriophage f1 that is required for DNA synthesis and repair. In solution, it exists as a dimer that binds two antiparallel ssDNA strands with high affinity in a cooperative manner, forming a left-handed helical protein–DNA filament. Here, we report on fluorescence studies of the interaction of G5P with different DNA oligonucleotides having a hairpin structure (molecular beacon, MB) with a seven base-pair stem (dT24-stem7, dT18-stem7), as well as with DNA oligonucleotides (dT38, dT24) without a defined secondary structure. All oligonucleotides were end-labeled with a Cy3-fluorophore and a BHQ2-quencher. In the case of DNA oligonucleotides without a secondary structure, an almost complete quenching of their strong fluorescence (with about 5% residual intensity) was observed upon the binding of G5P. This implies an exact alignment of the ends of the DNA strand(s) in the saturated complex. The interaction of the DNA hairpins with G5P led to the unzipping of the base-paired stem, as revealed by fluorescence measurements, fluorescence microfluidic mixing experiments, and electrophoretic mobility shift assay data. Importantly, the disruption of ssDNA’s secondary structure agrees with the behavior of other single-stranded DNA-binding proteins (SBPs). In addition, substantial protein-induced fluorescence enhancement (PIFE) of the Cy3-fluorescence was observed. KW - DNA KW - Protein KW - ssDNA KW - Fluorescence KW - Raman KW - G5P KW - Hairpin KW - Molecular beacon KW - Quencher KW - Amino Acids KW - SBP KW - SSB KW - Cy3 KW - PIFE KW - Protein-induced fluorescence enhancement KW - Protein–DNA filament KW - Single-stranded DNA-binding protein KW - Bacteriophage f1 KW - Oligonucleotides PY - 2023 DO - https://doi.org/10.1021/acs.jpcb.3c03669 SN - 1520-6106 VL - 127 IS - 38 SP - 8131 EP - 8138 PB - ACS Publications AN - OPUS4-58295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Sokolowski-Tinten, K. A1 - Bonse, Jörn A1 - Barty, A. A1 - Chapman, H.N. A1 - Bajt, S. A1 - Bogan, M.J. A1 - Boutet, S. A1 - Cavalleri, A. A1 - Düsterer, S. A1 - Frank, M. A1 - Hajdu, J. A1 - Hau-Riege, S. A1 - Marchesini, S. A1 - Stojanonovic, N. A1 - Treusch, R. ED - Stoian, R. ED - Bonse, Jörn T1 - In-Situ Observation of the Formation of Laser-Induced Periodic Surface Structures with Extreme Spatial and Temporal Resolution N2 - Irradiation of solid surfaces with intense ultrashort laser pulses represents a unique way of depositing energy into materials. It allows to realize states of extreme electronic excitation and/or very high temperature and pressure and to drive materials close to and beyond fundamental stability limits. As a consequence, structural changes and phase transitions often occur along unusual pathways and under strongly nonequilibrium conditions. Due to the inherent multiscale nature—both temporally and spatially—of these irreversible processes, their direct experimental observation requires techniques that combine high temporal resolution with the appropriate spatial resolution and the capability to obtain good quality data on a single pulse/event basis. In this respect, fourth-generation light sources, namely, short wavelength and short pulse free electron lasers (FELs), are offering new and fascinating possibilities. As an example, this chapter will discuss the results of scattering experiments carried out at the FLASH free electron laser at DESY (Hamburg, Germany), which allowed us to resolve laser-induced structure formation at surfaces on the nanometer to submicron length scale and in temporal regimes ranging from picoseconds to several nanoseconds with sub-picosecond resolution. KW - Laser-induced periodic surface structures, LIPSS KW - Capillary waves KW - Time-resolved scattering KW - Pump-probe experiments KW - Free electron laser PY - 2023 SN - 978-3-031-14751-7 SN - 978-3-031-14752-4 DO - https://doi.org/10.1007/978-3-031-14752-4_6 VL - 239 SP - 257 EP - 276 PB - Springer Nature Switzerland AG CY - Cham, Switzerland AN - OPUS4-57297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobetkii, Arcadii A1 - Mosinoiu, Laurentiu-Florin A1 - Caramarin, Stefania A1 - Mitrica, Dumitru A1 - Cursaru, Laura-Madalina A1 - Matei, Alexandru-Cristian A1 - Tudor, Ioan-Albert A1 - Serban, Beatrice-Adriana A1 - Ghita, Mihai A1 - Vitan, Nicoleta A1 - Witt, Julia A1 - Özcan Sandikcioglu, Özlem A1 - Postolnyi, Bogdan A1 - Pogrebnjak, Alexander T1 - Deposition and Characterization of Cu-Enhanced High-Entropy Alloy Coatings via DC Magnetron Sputtering N2 - Protection against microbiologically influenced corrosion (MIC) is critical for materials used in aquatic environments, as MIC accelerates material degradation and leads to faster structural failure. Copper (Cu) has the potential to substantially improve the MIC resistance in alloys. In this study, high-entropy alloy (HEA) coatings containing Cu were deposited using DC (Direct Current) magnetron sputtering to enhance the corrosion resistance and mechanical properties of various substrates. Two CuCrFeMnNi HEA compositions in the form of bulk alloys and PVD (Physical Vapor Deposition) coatings, with 5% and 10% Cu, were analyzed for their microstructural, mechanical, and anticorrosive characteristics. Deposition parameters were varied to select the optimal values. Microstructural evaluations using SEM-EDS (scanning electron microscopy and energy dispersive X-ray spectroscopy), XRD (X-ray diffraction), and AFM (atomic force microscopy) revealed uniform, dense coatings with good adhesion composed of dendritic and interdendritic BCC (body-centered cubic) and FCC (face centered cubic) structures, respectively. Microhardness tests indicated improved mechanical properties for the samples coated with developed HEAs. The coatings exhibited improved corrosion resistance in NaCl solution, the 10% Cu composition displaying the highest polarization resistance and lowest corrosion rate. These findings suggest that Cu-containing HEA coatings are promising candidates for applications requiring enhanced corrosion protection. KW - High-entropy alloys (HEAs) KW - DC magnetron sputtering KW - Cu-enhanced coatings KW - Corrosion resistance KW - Microstructural characterization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625561 DO - https://doi.org/10.3390/app15041917 SN - 2076-3417 VL - 15 IS - 4 SP - 1 EP - 14 PB - MDPI AN - OPUS4-62556 LA - eng 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 - 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 - TY - JOUR A1 - Smekhova, A. A1 - Kuzmin, A. A1 - Siemensmeyer, K. A1 - Luo, C. A1 - Taylor, J. A1 - Thakur, S. A1 - Radu, F. A1 - Weschke, E. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Xiao, B. A1 - Savan, A. A1 - Yusenko, Kirill A1 - Ludwig, A. T1 - Local structure and magnetic properties of a nanocrystalline Mn-rich Cantor alloy thin film down to the atomic scale N2 - The huge atomic heterogeneity of high-entropy materials along with a possibility to unravel the behavior of individual components at the atomic scale suggests a great promise in designing new compositionally complex systems with the desired multi-functionality. Herein, we apply multi-edge X-ray absorption spectroscopy (extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES), and X-ray magnetic circular dichroism (XMCD)) to probe the structural, electronic, and magnetic properties of all individual constituents in the single-phase face-centered cubic (fcc)-structured nanocrystalline thin film of Cr20Mn26Fe18Co19Ni17 (at.%) high-entropy alloy on the local scale. The local crystallographic ordering and component-dependent lattice displacements were explored within the reverse Monte Carlo approach applied to EXAFS spectra collected at the K absorption edges of several constituents at room temperature. A homogeneous short-range fcc atomic environment around the absorbers of each type with very similar statistically averaged interatomic distances (2.54–2.55 Å) to their nearest-neighbors and enlarged structural relaxations of Cr atoms were revealed. XANES and XMCD spectra collected at the L2,3 absorption edges of all principal components at low temperature from the oxidized and in situ cleaned surfaces were used to probe the oxidation states, the changes in the electronic structure, and magnetic behavior of all constituents at the surface and in the sub-surface volume of the film. The spin and orbital magnetic moments of Fe, Co, and Ni components were quantitatively evaluated. The presence of magnetic phase transitions and the co-existence of different magnetic phases were uncovered by conventional magnetometry in a broad temperature range. KW - Magnetism KW - High-entropy alloys KW - Reverse Monte Carlo (RMC) KW - Element-specific spectroscopy KW - Extended X-ray absorption fine structure (EXAFS), KW - X-ray magnetic circular dichroism (XMCD), PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578254 DO - https://doi.org/10.1007/s12274-022-5135-3 SN - 1998-0124 SP - 5626 PB - Springer AN - OPUS4-57825 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 - Smekhova, A. A1 - Kuzmin, A. A1 - Siemensmeyer, K. A1 - Abrudan, R. A1 - Reinholz, Uwe A1 - de Oliveira Guilherme Buzanich, Ana A1 - Schneider, M. A1 - Laplanche, G. A1 - Yusenko, Kirill T1 - Inner relaxations in equiatomic single-phase high-entropy Cantoralloy N2 - The superior properties of high-entropy multi-functional materials are strongly connected with their atomic heterogeneity through many different local atomic interactions. The detailed element-specific studies on a local scale can provide insight into the primary arrangements of atoms in multicomponent systems and benefit to unravel the role of individual components in certain macroscopic properties of complex compounds. Herein, multi-edge X-ray absorption spectroscopy combined with reverse Monte Carlo simulations was used to explore a homogeneity of the local crystallographic ordering and specific structure relaxations of each constituent in the equiatomic single-phase facecentered cubic CrMnFeCoNi high-entropy alloy at room temperature. Within the considered fitting approach, all five elements of the alloy were found to be distributed at the nodes of the fcc lattice without any signatures of the additional phases at the atomic scale and exhibit very close statistically averaged interatomic distances (2.54 – 2.55 Å) with their nearest-neighbors. Enlarged structural displacements were found solely for Cr atoms. The macroscopic magnetic properties probed by conventional magnetometry demonstrate no opening of the hysteresis loops at 5 K and illustrate a complex character of the long-range magnetic order after field-assisted cooling in ± 5 T. The observed magnetic behavior is assigned to effects related to structural relaxations of Cr. Besides, the advantages and limitations of the reverse Monte Carlo approach to studies of multicomponent systems like high-entropy alloys are highlighted. KW - Magnetism KW - High-entropy alloys KW - Reverse Monte Carlo (RMC) KW - Element-specific spectroscopy KW - Extended X-ray absorption fine structure (EXAFS) KW - X-ray absorption near edge structure (XANES) PY - 2022 DO - https://doi.org/10.1016/j.jallcom.2022.165999 SN - 0925-8388 VL - 920 SP - 1 EP - 31 PB - Elsevier AN - OPUS4-55457 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Smales, Glen Jacob A1 - Sprachmann, J. T1 - Datasets of Antiaromatic COFs associated with the publication "Antiaromatic Covalent Organic Frameworks Based on Dibenzopentalenes" N2 - X-ray scattering and sorption data associated with the publication "Antiaromatic Covalent Organic Frameworks Based on Dibenzopentalenes". X-ray scattering data is provided for COF and POP materials, including data from stability tests, as three-column ascii files with columns q (nm-1), I (m-1) and uncertainty on I, as well as being provided in 2θ. KW - X-ray scattering KW - SAXS KW - Covalent Organic Frameworks KW - Antiaromaticity KW - MOUSE PY - 2023 DO - https://doi.org/10.5281/zenodo.7509377 PB - Zenodo CY - Geneva AN - OPUS4-56868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Smales, Glen Jacob A1 - Pauw, Brian Richard A1 - Kolmangadi, Mohamed Aejaz T1 - X-ray scattering datasets associated with the publication "Molecular Mobility of Polynorbornenes with Trimethylsiloxysilyl side groups: Influence of the Polymerization Mechanism" N2 - X-ray scattering datasets for samples described in the 2022 publication "Molecular Mobility of Polynorbornenes with Trimethylsiloxysilyl side groups: Influence of the Polymerization Mechanism". This dataset includes both raw and processed X-ray scattering data for samples APTCN and MPTCN, alongside background measurements files (BKG). KW - X-ray scattering KW - SAXS KW - MOUSE KW - Membrane polymers KW - Microporous polymers PY - 2023 DO - https://doi.org/10.5281/zenodo.7621204 PB - Zenodo CY - Geneva AN - OPUS4-56972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -