Temperature and concentration depedence of hydrogen site occupancy in several rare earth dihydrides

Abstract

Neutron inelastic scattering and diffraction techniques were used to study the hydrogen site distribution in several rare earth dihydrides as a function of temperature and concentration. For Y, La, and Ce the fraction of hydrogen on octahedral sites is approximately a constant from 15 to 200 K followed by a decrease with increasing temperature. A model is presented which qualitatively explains this behavior.