Dresden 2017 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 32: Microstructure and Phase Transformations - detection methods

MM 32.5: Vortrag

Dienstag, 21. März 2017, 12:45–13:00, IFW B

Imaging and kinetics of MgH2 formation — •Efi Hadjixenophontos¹, Manuel Roussel¹, Toyoto Sato², Patrick Stender¹, Shin-ichi Orimo^2,3, and Guido Schmitz¹ — ¹Institut für Materialwissenschaft (IMW) University of Stuttgart, Heisenbergstrasse 3, 70569 Stuttgart GERMANY — ²Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 JAPAN — ³WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 JAPAN

Storage in metal hydrides is presented as one of the solutions to solve the hydrogen storage problem. MgH2 is one of the ideal materials, studied intensively for the hydrogen fuel based economy. This reversible system has however some drawbacks. Hydrogen and Mg are strongly bonded by a H bond, and this makes the stable compound unpractical for commercial use. During this work Mg thin films will enable us to monitor the growth process of the hydride and study the mechanism of hydride formation. Pd is used as a catalyst coating for decreasing the pressure and temperature of hydrogenation to 5bars and 100°C. The hydride formation has been followed by in-situ XRD characterization. Microscopic imaging of the co-existence of MgH2 and Mg is presented by SEM and TEM. The microstructure change is clearly visible in the micrographs, despite the fact that electron microscopy damages the hydride phase. These combined techniques are a great way to follow the kinetics of hydride formation within the layer,and study further the diffusion coefficients and mechanism of hydrogenation at 200°C and 300°C and at different pressures (1-100bars).