SPP 1959: Manipulation of matter controlled by electric and magnetic fields: Towards novel synthesis and processing routes of inorganic materials
Coordinator
Professor Dr.-Ing. Olivier Guillon
Grant period
2016 - 2025
Funding body
Deutsche Forschungsgemeinschaft
DFG
Identifier
G:(GEPRIS)274005202
Note: Electromagnetic field assisted synthesis and processing has the potential to generate materials with unprecedented functionality, to work them easily and significantly reduce the costs of required heat treating (currently 7% of the total primary energy demand in Germany is used for industrial heat treatments above 1000°C, which are required for the production of metal and ceramic products). Indeed, the use of external electric and magnetic fields with frequencies up to the microwave regime offers an additional degree of freedom to synthesize materials, tailor microstructures and final properties through acceleration or retardation of reactions, stabilization of metastable phases, independent control of grain growth, and the possibility of near-net shape manufacturing with high strain rates under reduced stress and temperature. For example: - Nanostructured permanent magnets textured by spinodal decomposition under magnetic field show drastic improvement of magnetic properties, which are required for upcoming technologies (high-performance electric hybrid vehicles and generators for wind turbines) - Most nanostructured, out-of-thermodynamical equilibrium thermoelectrics can only be obtained by electric field assisted synthesis and sintering - Electroplasticity can lead to dramatic changes in deformability of solid metals at temperatures and times that would not result in observable shape changes without an electrical current, making it a very promising direction for processing. On the other hand, field driven matter transport leading to accelerated degradation can be observed in electrochemical and electronic devices. A comprehensive and detailed knowledge about these phenomena will help to improve life time by avoiding critical geometries, field gradients, interfaces and combinations of distinct materials. The emerging field of temperature dependent Electro-Chemo-Mechanics of solids will thus have a high scientific and technological impact over the next decade if multidisciplinary research efforts are intensified. Although evidence for the interactions between external electromagnetic fields, diffusion and deformation mechanisms have been gathered over the years, a global yet detailed understanding of the interactions between electromagnetic fields and solid-state matter transport is far from being reached. By establishing a coordinated research programme, we aim to provide a rational, comprehensive knowledge based on experimental evidence and complementary numerical simulations for intentionally using electromagnetic energy to mamipulate matter in metals, intermetallics, oxide and non-oxide ceramics as bulk, thin or thick films. In all these processes, defects such as single or clustered point defects, dislocation networks, interfaces between two reacting solids or crystalline phases (grain boundaries) play a key role. Therefore, a fundamental question to address is: What are the interplays between electric / magnetic fields and matter transport, defect formation, structure and mobility? These properties will determine the response of the whole material and its processing ability. An essential goal is to link atomistic mechanisms to macroscopic behaviour in a multi-scale modelling scheme. Length scales ranging from angstroms to millimetres and time scales from picoseconds to a few hours are characteristic of the processes considered. By quantifying thermal and athermal effects, taking advantage of numerical simulations and experimental approaches, the controlling mechanisms can be clarified at all levels and modelled. Recent advances in magnet technology, in-situ in-operando electron microscopy and spectroscopy techniques, characterization by synchrotron X-ray and neutron radiations, in-situ mechanical testing now enable to monitor in real time dynamic processes with high spatial and temporal resolutions. Some of the best facilities worldwide are located in Germany and will significantly contribute to the success of this programme. By bundling the efforts of different scientific communities (chemical solid state and surface research, condensed matter physics, mineralogy and crystallography, materials science and engineering, and mechanics) this new priority programme will enable to close the gap between fundamentals and technological development at an unprecedented level and pace. The unique expertise gained will on the one hand pave the way for novel, energy-efficient, environmentally friendly, less costly processing routes for inorganic materials. On the other hand, the fundamental understanding has a wide-ranging impact on the remediation of irreversible degradation in electrochemical devices such as energy converters (solid oxide electrolysers) or the development of solid-state ion-conducting batteries.
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