Synthesis and Determination of the Crystal Structure of Hydrides of Er(M, V)2, where M = Fe or Co, Compounds

Abstract

We study the process of formation of the Laves phases AB2 in Er(M, V)2 (M = Fe or Co) systems and determine their hydrogen-sorption properties. The crystal structure of parent compounds and their saturated hydrides is analyzed by the X-ray diffraction method. It is shown that these compounds absorb hydrogen at pressures of 0.1– 0.12 MPa without amorphization. The formation of the ErFe2 hydride is accompanied by the transformation of a cubic MgCu2-type structure into a trigonal TbFe2-type structure. Even an insignificant substitution of Fe with V or Co leads to an increase in the hydrogen-sorption capacity and prevents the changes in the crystal structure.