6533b858fe1ef96bd12b5764

RESEARCH PRODUCT

Theoretical and experimental study of the structural stability ofTbPO4at high pressures

subject

description

We have performed a theoretical and experimental study of the structural stability of terbium phosphate at high pressures. Theoretical ab initio total-energy and lattice-dynamics calculations together with x-ray diffraction experiments have allowed us to completely characterize a phase transition at {approx}9.8 GPa from the zircon to the monazite structure. Furthermore, total-energy calculations have been performed to check the relative stability of 17 candidate structures at different pressures and allow us to propose the zircon {yields} monazite {yields} scheelite {yields} SrUO{sub 4}-type sequence of stable structures with increasing pressure. In this sequence, sixfold P coordination is attained for the SrUO{sub 4}-type structure above 64 GPa. The whole sequence of transitions is discussed in association with the high-pressure structural behavior of oxides isomorphic to TbPO{sub 4}.