Regensburg 2010 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 26: Poster Session

MM 26.52: Poster

Tuesday, March 23, 2010, 14:45–16:30, Poster C

Hydrogen absorption behavior of nano-crystalline Mg thin films — •Helmut Takahiro Uchida, Astrid Pundt, and Reiner Kirchheim — Institut fuer Materialphysik, Friedrich-Hund-Platz 1, D-37077, Goettingen, Germany

Hydrogen absorption behavior of nano-crystalline Mg thin films are electrochemically investigated at room temperature. 20nm Pd-capped nanocrystalline Mg films of different thicknesses were prepared in an UHV chamber, by means of ion beam sputter deposition under Ar-atmosphere at the pressure of 2,5*10E-4 mbar. Nano-crystalline Mg films were deposited on Si (100) substrates for P-C-T measurements of hydriding, and on annealed Pd-substrates with thickness of less than 0.25mm for hydrogen permeation measurements. All the films were covered by a 20 nm thick layer of Pd in order to prevent oxidation. The influence of loading current density on hydrogenation property were observed by measuring electromotive force (EMF). Diffusion coefficient of hydrogen in nano-crystalline Mg thin films at room temperature are estimated at several hydrogen concentration, and the impact of grain boundary on hydrogenation property is discussed. XRD measurements using a Phillips X-Pert diffractometer with a Co-K alpha radiation were performed before and after hydrogenation in order to check the phase transition and change of texture in the sample.