Solubility of hydrogen in Zr<inf>1 - x</inf>Ho<inf>x</inf>Co<inf>2</inf> (0 ≤ x ≤ 1) alloys

Hydrogen absorption studies were carried out on the pseudobinary system Zr1 - xHoxCo2 (x = 0.2, 0.4, 0.6 and 0.8) belonging to the C15-type Laves phases in the temperature range RT≤ T (°C) ≤ 300 and the pressure range 0.001 ≤ P (bar) ≤ 1. Hydrogen absorption was found to increase with increasing holmium concentration. For the compositions x = 0.6 and 0.8, the pressure-composition isotherms indicated the occurrence of a phase transformation. The relative partial molar enthalpy and entropy of hydrogen solution calculated for all the concentrations were found to be approximately -(7-18) kJ (mol H)-1 and -(10-48) J K-1 (mol H)-1 respectively. © 1991.