A5050068849- Glass properties and applications
- Phase-change materials and chalcogenides
- Metallic Glasses and Amorphous Alloys
- Solidification and crystal growth phenomena
- Thermodynamic and Structural Properties of Metals and Alloys
- Material Dynamics and Properties
- Aluminum Alloy Microstructure Properties
- Crystal Structures and Properties
- Intermetallics and Advanced Alloy Properties
- Chalcogenide Semiconductor Thin Films
- nanoparticles nucleation surface interactions
- Metallurgical and Alloy Processes
- Electronic Packaging and Soldering Technologies
- High Entropy Alloys Studies
- High-Temperature Coating Behaviors
- Aluminum Alloys Composites Properties
- Advanced ceramic materials synthesis
- Solid-state spectroscopy and crystallography
- X-ray Spectroscopy and Fluorescence Analysis
- Mineralogy and Gemology Studies
- Chemical Thermodynamics and Molecular Structure
- Metallurgical Processes and Thermodynamics
- X-ray Diffraction in Crystallography
- Additive Manufacturing Materials and Processes
- Nonlinear Optical Materials Studies
Leibniz Institute for Solid State and Materials Research
2015-2024
TU Dresden
2012-2019
Advanced Institute of Materials Science
2016
Tohoku University
2016
University of Cambridge
2016
Chemnitz University of Technology
2002-2011
Japan Synchrotron Radiation Research Institute
2010
Japan Science and Technology Agency
2010
Czech Academy of Sciences, Institute of Physics
2005-2006
The structure of amorphous ${\mathrm{Ge}}_{2}{\mathrm{Sb}}_{2}{\mathrm{Te}}_{5}$ and $\mathrm{Ge}{\mathrm{Sb}}_{2}{\mathrm{Te}}_{4}$ phase-change alloys was investigated by high energy x-ray diffraction, extended x-ray-absorption fine structure, neutron diffraction. reverse Monte Carlo simulation technique used to generate large scale atomic models compatible with all experimental data sets. Simulations revealed that Ge-Ge bonding is present already in...
Abstract Metallic glasses (MGs) inherit their amorphous structure from the liquid state, which predetermines ability to withstand high loads approaching theoretical limit. However, absence of slip systems makes them very sensitive type loading and extremely brittle in tension. The latter can be improved by precipitation ductile crystals, suppress a catastrophic propagation shear bands glassy matrix. Here we report novel approach obtain MG-matrix composites with tensile ductility flash Joule...
At room temperature, plastic flow of metallic glasses (MGs) is sharply localized in shear bands, which are a key feature the deformation MGs. Despite their clear importance and decades study, conditions for formation structural evolution multiplication mechanism still under debate. In this work, we investigate local at bands new phase-separated bulk MGs containing glassy nanospheres exhibiting exceptional plasticity compression. It found that within band dissolve through mechanical mixing...
Abstract The density of liquid Al – Fe and Ni binary alloys have been determined over a wide temperature range by non-contact technique combining electromagnetic levitation optical dilatometry. composition dependences the are analysed. A negative excess volume correlates with enthalpy mixing, compound forming ability chemical short-range ordering in alloys.
Abstract A combination of complementary high-energy X-ray diffraction, containerless solidification during electromagnetic levitation and transmission electron microscopy is used to map in situ the phase evolution a prototype Cu-Zr-Al glass flash-annealing imposed at rate ranging from 10 2 3 K s −1 cooling liquid state. Such experimental techniques provides hitherto inaccessible insight into phase-transformation mechanism its kinetics with high temporal resolution over entire temperature...
Metallic-glass–crystal composites of Cu47.5Zr47.5Al5 and Cu10Zr7-reinforced Cu46.5Zr48Al4Nb1.5 nanocrystalline materials are obtained by flash-annealing metallic-glass ribbons. In situ high-energy X-ray diffraction reveals the deformation mechanism alloys upon tensile loading. For materials, a small remaining amount metallic glass and/or presence Cu10Zr7 phase significantly increase value yield stress while maintaining good ductility. general, exhibit reversible martensitic transformation...
The structure of sputtered amorphous Ge(2)Sb(2)Te(5) was investigated by high energy x-ray diffraction, neutron diffraction and Ge-, Sb- Te K-edge EXAFS measurements. five datasets were modelled simultaneously in the framework reverse Monte Carlo simulation technique. It found that apart from Te-Sb Te-Ge bonds existing crystalline phases, Ge-Ge Sb-Ge bonding is also significant Ge(2)Sb(2)Te(5). According to our results, all components obey '8-N' rule.
Abstract Phase-change materials exhibit fast and reversible transitions between an amorphous a crystalline state at high temperature. The two states display resistivity contrast, which is exploited in phase-change memory devices. technologically most important family of consists Ge-Sb-Te alloys. In this work, we investigate the structural, electronic kinetic properties liquid Ge 2 Sb Te 5 as function temperature by combined experimental computational approach. Understanding phase to clarify...
The temperature-dependent viscosity η(T) is measured for the equilibrium liquid of chalcogenide Ag-In-Sb-Te (AIST), first time this has been reported a material actual interest phase-change memory. measurements, in range 829-1254 K, are made using an oscillating-crucible viscometer, and show with high fragility low viscosity, similar to pure metals. Combining high-temperature measurements values inferred from crystal growth rates supercooled allows form be estimated over entire temperature...
GeTe is a prototypical phase-change material employed in data storage devices. In this work, the atomic structure of liquid studied by x-ray and neutron diffraction temperature range from 1197 to 998 K. The dynamic viscosity measured 1273 953 K, which 55 K below solidification point, using an oscillating-cup viscometer. density between 1293 973 determined high-energy $\ensuremath{\gamma}$-ray attenuation method. experiments are complemented with ab initio molecular dynamics (AIMD)...
Time- and temperature-resolved phase formation in the equiatomic NbTiVZr refractory high-entropy alloy has been studied situ using high-energy synchrotron X-ray diffraction high-speed video imaging during non-equilibrium solidification. Phase is shown to be dependent on solidification conditions. When melt undercooled over 80 K it crystallizes as a bcc single-phase solid solution despite solute partitioning between dendrites interdendritic regions. sample for some time kept semisolid state,...
Abstract Chalcogenide phase‐change materials combine a remarkable set of properties that makes them promising candidates for future non‐volatile memory applications. Binary data storage exploits the high contrast in electrical and optical between covalent amorphous metavalent crystalline phase. Here authors perform an analysis liquid phase kinetics material Ge 3 Sb 6 Te 5 , which is key to ultrafast switching speeds. By employing four experimental techniques, viscosity measured over sixteen...