Regensburg 2022 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 17: Hydrogen in Materials: Hydrogen Storage

MM 17.4: Talk

Tuesday, September 6, 2022, 14:45–15:00, H46

ETEM studies on hydride precipitation and growth in Mg films — Magnus Hamm¹, Marian David Bongers¹, Vladimir Rodatis¹, Stefan Dietrich², Karl-Heinz Lang², and •Astrid Pundt² — ¹Göttingen University, Institute of Materials Physics (IMP), Göttingen, Germany — ²Karlsruhe Institute of Technology (KIT), Institute for Applied Materials - Materials Science and Engineering (IAM-WK), Karlsruhe, Germany

Understanding solute-induced phase transformations is crucial in a variety of research fields such as catalysis, memory switching or energy storage. We present solute-induced phase transformations studied on the model system magnesium-hydrogen (MgH) which provides high lattice expansion during the phase transformation. In situ precipitation and growth of MgH₂ is studied in an environmental transmission electron microscope (ETEM), combining electron energy loss spectroscopy (EELS) and various imaging techniques. We observe that the Mg-hydride (MgH₂) formation proceeds through the formation of nanocrystals that are separated by low-angle grain boundaries. We attribute this microstructural change to large strains and stresses between the matrix and the MgH₂ created during the transformation. [1] M. Hamm et al., Int. J. Hydr. Energy 44 (2019) 32112.