THE GAMMA-PHASE OF CANI5+H2

Detailed pressure-composition measurements at 273 K and in-situ X-ray diffractometry measurements at room temperature of the approximate composition range 4. 0 less than x less than 6. 0 in CaNi//5H//x have shown that the region previously described as the gamma phase, 4. 5 less than x less than 5. 5, actually consists of two narrower solution ranges, gamma prime and gamma double prime , separated by a gamma prime plus gamma double prime coexistence range. The most detailed results give composition limits in absorption of: gamma prime , 4. 70 less than x less than 5. 15; gamma prime plus gamma double prime , 5. 15 less than equivalent to x less than equivalent to 5. 30; gamma double prime , 5. 30 less than x less than 5. 60. The metal atom sublattices of both solutions have orthorhombic symmetry.