Publication at Faculty of Mathematics and Physics |
2015
Abstract
Hydrogenation properties of the intermetallic compounds R2Ni2Al (R = Gd, Er, Lu) and R2Ni2Sn (R = Gd, Tb), crystallizing with orthorhombic W2CoB2-type structure (oI10, Immm), have been studied. These intermetallics absorb up to 5.5 hydrogen atoms per formula unit at room temperature under the hydrogen pressure 0.8 bar.
The Al-containing compounds exhibit extremely fast hydrogenation kinetics, whereas several hours incubation period is required for the Sn-containing compounds. Hydrogenation results in strongly anisotropic unit-cell volume expansion up to 21% prevailing in b-axis with concomitant lattice contraction in a-axis.