Low-temperature polymorphic transition in highly compressed uranium dioxide

Abstract

The Mayer group expansion method is extended on the low-temperature solids where quantum effects cannot be ignored and applied to the prediction of polymorphic transition line between cubic Fm3m and orthorhombic Pnma phases in the highly compressed ionic crystal of uranium dioxide. The temperature dependence of the transition pressure and volume changes are evaluated and the results are compared with existing experimental data and ab initio predictions.