TY - CONF A1 - Radtke, Martin T1 - Von der Bronzezeit ins 21. Jahrhundert - Materialcharakterisierung mit SyXRF an der BAMline T2 - 17. Sitzung des Fachausschusses Zerstörungsfreie Materialcharakterisierung, DGZFP CY - Berlin, Germany DA - 2009-11-10 PY - 2009 AN - OPUS4-20772 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Eilbracht, H. A1 - Armbruster, B. A1 - Reichen, I. T1 - Das Hiddensee-Projekt T2 - Kulturgut durchleutet - Strahlung trifft Kulturgut (Symposium) CY - Berlin, Germany DA - 2009-11-04 PY - 2009 AN - OPUS4-20771 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharf, O. A1 - Bjeoumikova, S. A1 - Gubzhokov, Renat A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Wedell, R. A1 - Soltau, H. A1 - Ihle, S. T1 - An energy and spatial resolving X-Ray camera T2 - Technart 2011 CY - Berlin, Germany DA - 2011-04-26 PY - 2011 AN - OPUS4-23079 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Grunewald, Christian A1 - Emmerling, Franziska A1 - Radtke, Martin A1 - Scharf, Oliver T1 - Archäometrie an der BAMline T2 - Lange Nacht der Wissenschaften, BAM, BESSY II CY - Berlin, Germany DA - 2010-06-05 PY - 2010 AN - OPUS4-21379 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - XRF using synchrotron radiation T2 - Vienna summer school 2010 "Radiation physics in cultural heritage studies" CY - Vienna, Austria DA - 2010-09-21 PY - 2010 AN - OPUS4-23263 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharf, O. A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Buzanich, Günter A1 - Bjeoumikova, S. A1 - Gubzhokov, R. A1 - Langhoff, N. A1 - Soltau, H. A1 - Wedell, R. A1 - Ordavo, I. T1 - A novel device for elemental distribution imaging: A color X-Ray Camera T2 - Jahrestagung der Deutschen Gesellschaft für Biomaterialien (DGBM) CY - Giessen, Germany DA - 2011-11-01 PY - 2011 AN - OPUS4-23974 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Automated quantum-chemical bonding analysis with workflow tools N2 - Bonds and local atomic environments are crucial descriptors of material properties. They have been used to create design rules and heuristics and as features in machine learning of materials properties. Implementations and algorithms (e.g., ChemEnv and LobsterEnv) for identifying local atomic environments based on geometrical characteristics and quantum-chemical bonding analysis are nowadays available. Fully automatic workflows and analysis tools have been developed to use quantum-chemical bonding analysis on a large scale. The lecture will demonstrate how our tools, that assess local atomic environments and perform automatic bonding analysis, help to develop new machine learning models and a new intuitive understanding of materials. Furthermore, other recent workflow contributions to the Materials Project software infrastructure (pymatgen, atomate2) related to phonons and machine-learning potentials will be discussed. T2 - ADIS Workshop 2023 CY - Tegernsee, Germany DA - 29.10.2023 KW - Automation KW - Materials Properties KW - DFT KW - Workflows KW - Machine Learning KW - Thermodynamic Properties PY - 2023 AN - OPUS4-58745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-driven chemical understanding with bonding analysis N2 - Bonds and local atomic environments are crucial descriptors of material properties. They have been used to create design rules and heuristics and as features in machine learning of materials properties. Implementations and algorithms (e.g., ChemEnv and LobsterEnv) for identifying local atomic environments based on geometrical characteristics and quantum-chemical bonding analysis are nowadays available. Fully automatic workflows and analysis tools have been developed to use quantum-chemical bonding analysis on a large scale. The lecture will demonstrate how our tools, that assess local atomic environments and perform automatic bonding analysis, help to develop new machine learning models and a new intuitive understanding of materials.[5,6] Furthermore, the general trend toward automation in density functional-based materials science and some of our recent contributions will be discussed. T2 - Seminar of the Department of Chemistry at Imperial College London CY - Online meeting DA - 20.02.2024 KW - Automation KW - Magnetism KW - Bonding Analysis KW - Machine Learning PY - 2024 AN - OPUS4-59546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bustamante Pineda, Joana Cecibel A1 - George, Janine T1 - Sulfide-Argyrodites: Thermal properties within the QHA N2 - Argyrodite-type materials have lately sparked a lot of research interest due to their thermoelectric properties. One promising candidate is canfieldite (Ag8SnS6), which has a Pna21 orthorhombic crystal structure at room temperature (RT). Recently, experimentalists have found a new low-temperature (LT) phase transition of canfieldite at 120K. Therefore, we investigate structural, vibrational and thermodynamic properties of Ag8SnS6 at room- and low-temperature employing density-functional theory (DFT) and lattice dynamics computations. Thermal properties calculations were based on the quasi-harmonic approximation (QHA) as implemented in phonopy. We achieve good agreement with experiments. Lattice parameters were overestimated by 2%, and thermal properties such as the constant-pressure heat capacity Cp are very close to experimental measurements. Our simulations also reveal a possible new phase transition at around 312 K. Furthermore, we compared RT and LT Ag8SnS6 Grüneisen parameters with some argyrodites analogues, Ag8TQ6 (T = Si, Ge, Ti and Sn; Q = S, Se), finding a relationship between the anharmonicity and low thermal conductivity. T2 - SALSA Make and Measure Conference CY - Berlin, Germany DA - 13.09.2023 KW - Thermoelectric materials KW - DFT KW - QHA KW - Grüneisen parameter PY - 2023 AN - OPUS4-58368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Von Ägypten bis Hiddensee Analyse von Gold mit Synchrotronstrahlung III N2 - Gold ist eines der sieben schon im Altertum bekannten Metalle und wurde wg. seines Glanzes und seiner Seltenheit von alters her als Tauschmittel und zur Herstellung von Schmuck benutzt. Außerdem ist es einfach bearbeitbar und weitestgehend gegen chemische Einflüsse resistent. Die Untersuchungen von Gold mit synchrotronstrahlungsangeregter Röntgenfluoreszenzanalyse sind zerstörungsfrei und geben Auskunft über die in der untersuchten Probe vorhandenen chemischen Elemente. Bei den hier vorgestellten Untersuchungen an der BAMline stehen Fragestellungen wie Herkunft, Herstellungsverfahren und Zusammengehörigkeit von Goldfunden im Vordergrund. Die verschiedenen Fragestellungen werden an einer Reihe von Beispielen erläutert die vom Wikingerschatz aus Hiddensee über die Himmelsscheibe von Nebra bis hin zu Funden aus Ägypten langen. Der Fund von Bernstorf wird ausführlich diskutiert. T2 - Vorlesung FU Berlin Einführung in die Archäometrie CY - Berlin, Germany DA - 06.11.2020 KW - Synchrotron KW - BAMline KW - XRF KW - Gold KW - Archäometrie PY - 2020 AN - OPUS4-51893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fittschen, U. A1 - Lutz, C. A1 - Beuermann, S. A1 - Turek, T. A1 - Kunz, U. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin T1 - Element Species Determination in Polymer Electrolyte Membranes N2 - Polymer electrolyte membranes (PEM) are polymers which act as separator in an electrochemical cell and allow ionic charge flow to close the circuit. Widely used membranes are perfluorinated sulfonic-acid (PFSA) ionomers (e.g. Nafion™), a class of ion-conducting polymers with remarkable ion conductivity and chemical-mechanical stability. A nanoscopic water system around the sulfonic acid capped side-chains of the otherwise hydrophobic polymer allows the ion transport. Only approx. 14 molecules of water per sulfonic group are present in the fully hydrated state. In vanadium redox flow batteries (VRFB) ideally only protons are transported. The weak ion selectivity of Nafion™ is the main cause for the transportation of vanadium, briefly vanadium crossover, in VRFBs a system we have investigated more closely, lately. The consequences of crossover are a concentration imbalance and a self-discharge of the battery, which leads to a decrease of the capacity. The development of efficient energy storage systems is crucial for the transformation towards a renewable energy based economy. The VRFB has a great potential as a commercial electrochemical energy storage system due to properties including, but not limited to, no cross-contamination, a long cycle-life and a theoretically unlimited capacity. VRFB consists of two half-cells, which are linked to electrolyte tanks and separated by a membrane. The membrane plays a major role in overall cell performance. So far, vanadium transportation models, which include diffusion, migration, electroosmotic convection and pressure gradients, are inconsistent. There is no agreement in the literature on the diffusion coefficients of vanadium species (e.g. published diffusion coefficients of V2+ are located between 3.13·10-12 m²s-1 and 9.44·10-12 m²s-1) indicate that thevanadium crossover is not well understood and there is a lack on a more fundamental level. Since the membrane transport is the rate-determining step of the crossover as well as of the proton exchange it is extremely important to understand these phenomena on a fundamental level. This will eventually allow us to design better membranes. Alternative materials need to show equivalent performance compared with Nafion™ and ideally be more selective regarding ion cross-membrane transport.There are several options to approach the chemistry i.e. the interaction of dissolved and bound ions inside the confined water body of ionomeric membranes. Vanadium ions are a versatile model as UV/VIS data can be used to distinguish between the 5 species V2+, V3+, VO2+, VO2+ and V2O33+ of the electrolyte. Infrared spectroscopy has been applied to study the interaction of sulfonic groups and the ions. Molecular dynamic modeling is another approach to study the distribution and distances of ions. We now introduce X-ray absorption near edge structure spectroscopy (XANES) to study species and species changes inside Nafion™ and a novel membrane based on poly(1,1-difluoroethylene) (PVDF). We evaluated the methods and investigated the influence of irradiation, temperature and hydration on the measurements. T2 - Denver X-Ray Conference CY - Online meeting DA - 03.08.2020 KW - Batteries KW - BAMline KW - XANES PY - 2020 AN - OPUS4-51910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lutz, C. A1 - Beuermann, S. A1 - Turek, T. A1 - Kunz, U. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Fittschen, U. T1 - Investigation on Vanadium Crossover in Nafion ™ and Novel PVDF Based Membranes for Vanadium Redox Flow Batteries N2 - Vanadium redoxflow batteries (VRFB)are currently one of the most promising candidates for stationary energys torage.For large scale applications the ion conducting membranes currently in use need to be improved. Ideally,they need to become more cost efficient and selective regarding the vanadium crossover.For a better understanding of the vanadium crossover, the development of reliable analytical methods and procedures, that elucidate uptake and transport of vanadium ions in the membrane, is necessary. First, we present the uptake of V2+,V3+,VO2+, VO2+ and V2O33+ in Nafion™ and in a novel membrane based onpoly(1,1-difluoroethylene)(PVDF). In preliminary discharge/charge experiments the ETFE-based membrane, the precursor of PVDF-based membrane, performed comparable to Nafion™. The methods of choice for speciation are UV/Vis and X-ray absorption near edge structure spectroscopy (XANES). According to the results, V2O33+, formed from VO2+ and VO2+, diffuses also into the membrane. In present models, the diffusion of V2O33+ is neglected. In addition,we study whether reactions could take place inside the membranes’ nanoscopic water body using XANES. Exposing Nafion™ from one site with V3+a nd from the other site with VO2+ realized the experiment. The results verified that VO2+ was formed inside the membrane. However,in present models reactions inside the membrane are neglected, too. T2 - Denver X-Ray Conference CY - Online meeting DA - 03.08.2020 KW - Batteries KW - BAMline KW - XANES KW - VRF PY - 2020 AN - OPUS4-51909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Streli, Christina T1 - S²XAFS: A new experimental setup for time-resolved X-ray absorption fine structure spectroscopy in a 'single shot' N2 - A newly developed EXAFS setup is presented. It enables both time- and spatially resolved EXAFS information simul-taneously in a single shot. First tests of this setup were performed at the BAMline @ BESSY-II (Berlin, Germany). A primary broadband beam generated by a filter/X-ray-mirror combination passes through the sample and is then dif-fracted by a convexly bent Si (111) crystal. This results in a divergent beam which is collected by an area sensitive detector, in a θ-2θ-geometry. Beside tests on metal foils the first in situ measurements were successfully carried out. The case-study deals with research on Zn-based Metal-Organic-Frameworks (MOF) with medical/pharmaceutical applications. This hot topic of MOFs research concerns drug delivery and encapsulation of therapeutically relevant proteins (e.g. BSA). Questions like how does a certain protein influences the coordination of Zn can be answered with this new setup. We were able to track structural changes within a 1s time resolution. T2 - CSI XL CY - Pisa, Italy DA - 11.06.2017 KW - XAFS KW - Time-resolved KW - Dispersive KW - In-situ measurement PY - 2017 AN - OPUS4-41052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühn, Andreas A1 - Scharf, Oliver A1 - Ordavo, I. A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Ostermann, Markus A1 - Berger, Achim A1 - Panne, Ulrich T1 - Schnelle ortsaufgelöste Messungen der Elementverteilung in TXRF-Proben T2 - Konferenz PRORA 2011 CY - Berlin, Germany DA - 2011-11-24 PY - 2011 AN - OPUS4-24981 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Pernicka, E. A1 - Reiche, I. A1 - Riederer, J. T1 - Non-destructive analyses by PIXE and Sy-XRF: Indian Miniatures, Renaissance metal point drawings and the Sky Disc of Nebra T2 - ECAART-8 8th European Conference on Accelerators in Applied Research and Technology CY - Paris, France DA - 2004-09-20 PY - 2004 AN - OPUS4-5058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reiche, I. A1 - Riederer, J. T1 - Silberstiftzeichnungen - Zerstörungsfreie Spurenanalyse mit Synchrotronstrahlung T2 - Papier-Restaurierung / 10. IADA-Kongress (Internationale Arbeitsgemeinschaft der Archiv-, Bibliotheks- und Graphikrestauratoren) CY - Göttingen, Germany DA - 2003-09-21 PY - 2003 AN - OPUS4-3080 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Riesemeier, Heinrich A1 - Reiche, I. A1 - Riederer, J. A1 - Roth, M. T1 - BAMline meets Dürer and Van Eyck: Spatialy resolved SR-XRF analyses of silver point drawings and thier mysterious inscriptions T2 - ICXOM: 17th International Congress on X-ray Optics and Microanalysis CY - Chamonix, France DA - 2003-09-22 PY - 2003 AN - OPUS4-3794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reiche, I. A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Bevers, H. A1 - Duval, A. A1 - Roth, M. T1 - Synchrotron radiation on the traces of famous painters:XRF analyses of silverpoint drawing by Dürer, Holbein, Van Eycken and Rembrandt T2 - Synchrotron Radiation in Art and Archaeology; ESRF-CNRS Joint Workshop CY - Grenoble, France DA - 2005-02-09 PY - 2005 AN - OPUS4-7462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merchel, Silke A1 - Berger, Achim A1 - Görner, Wolf A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vogl, Jochen A1 - Frisch, A. A1 - Reiche, I. T1 - Kunst- und Kulturgüter unter "Beschuss" T2 - GDCh-Jahrestagung Chemie 2003, Fachgruppentagung der Fachgruppe Nuklearchemie CY - Munich, Germany DA - 2003-10-06 PY - 2003 UR - http://www.meteoroids.de/docs/poster/KunstKulturGDChMercheletal2003.pdf AN - OPUS4-4921 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merchel, Silke A1 - Berger, Achim A1 - Görner, Wolf A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vogl, Jochen A1 - Frisch, A. A1 - Reiche, I. A1 - Riederer, J. T1 - Kunst- und Kulturgüter unter "Beschuss" T2 - 13. Jahrescolloquium der Interessengemeinschaft Atomspektroskopie CY - Berlin, Germany DA - 2003-11-19 PY - 2003 UR - http://www.meteoroids.de/docs/poster/KunstKulturGDChMercheletal2003.pdf AN - OPUS4-4922 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -