Investigation of nanocrystalline Gd films loaded with hydrogen

Abstract
The present work reports on microstructure studies of hydrogen-loaded nanocrystalline Gd films prepared by cold cathode beam sputtering on sapphire (112¯0) substrates. The Gd films were electrochemically step-by-step charged with hydrogen and the structural development with increasing concentration of absorbed hydrogen was studied by transmission electron microscopy and in-situ   X-ray diffraction using synchrotron radiation. The relaxation of hydrogen-induced stresses was examined by acoustic emission measurements. In the low concentration range absorbed hydrogen occupies preferentially vacancy-like defects at GBs typical for nanocrystalline films. With increasing hydrogen concentration hydrogen starts to occupy interstitial sites. At the solid solution limit the grains gradually transform into the ββ-phase (GdH2). Finally at high hydrogen concentrations xH>2.0xH>2.0 H/Gd, the film structure becomes almost completely amorphous. Contrary to bulk Gd specimens, the formation of the γγ-phase (GdH3) was not observed in this work.

Citation
Investigation of nanocrystalline Gd films loaded with hydrogen 2015 Journal of Alloys and Compounds

Publisher
Elsevier BV

Journal
Journal of Alloys and Compounds

DOI
10.1016/j.jallcom.2014.12.156

Additional Links
http://linkinghub.elsevier.com/retrieve/pii/S0925838814030849

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