Vacancy induced anomalies in the laves phase CeNi2

For the cubic Laves phase CeNi2, pronounced anomalies have been observed in the lattice spacings and microstructures with quenching from elevated temperatures and in the high temperature thermal expansion behaviour. All these effects have been attributed to the production of a high concentration of vacancies at high temperatures. A low vacancy formation energy is indicated by the temperature dependence of the vacancy concentration. The vacancies are thought to be associated with the variable valency state of the cerium atoms, and with the critical electron concentration of the cubic Laves phase. (orig.)