Structural studies of Laves phases ZrCo(V1-xCrx) with 0 <= x <= 1 and their hydrides

Laves phases of the series ZrCo(V1-xCrx) with 0 less than or equal to x les s than or equal to 1 have been synthesised with the hexagonal C14-type stru cture. We have analyzed the structure of the alloys by X-ray and neutron di ffraction, and determined the sites occupied by transition metals with the V/Cr substitution. The positions of hydrogen atoms in the structure and the occupation of the different interstitial sites of the hydrides have been d etermined. The effects of the V/Cr substitution have been studied with rega rd to the phase stability, the maximum hydrogen content and the hydrogen si te stability. P-c-T measurements show a good reversibility of the hydrogen uptake. (C) 1999 Elsevier Science S.A. All rights reserved.