Hydrogen ordering and H-induced phase transformations in Zr-based intermetallic hydrides

Crystal chemistry aspects of hydrogen behaviour in the zirconium-iron inter metallic deuterides (hydrides), Zr2FeD1.80-5.00, Zr3FeD1.27-6.70 and Zr4Fe2 O0.6H7.80, were studied with a focus on the application of high resolution powder neutron diffraction: The effects of crystal structure, chemical comp osition of the metal matrices, temperature and hydrogen contents on prefere nces in the interstices occupation and H ordering were investigated and dis cussed in relation to the H absorption-desorption properties. The Hydrogena tion-Disproportionation-Desorption-Recombination process was successfully a pplied to all materials studied, including the first reported example of an oxygen-containing compound, Zr4Fe2O0.6. (C) 1999 Elsevier Science S.A. All rights reserved.