High-pressure structures of α- and δ-ZrMo2O8

Abstract

In situ high-pressure synchrotron X-ray powder diffraction studies of trigonal α-ZrMo2O8, zirconium molybdate, have been performed from ambient conditions to 1.9 GPa, over the α–δ phase transition at 1.06–1.11 GPa. The monoclinic structure of δ-ZrMo2O8, stable between 1.1 and 2.5 GPa at 298 K, has been solved by direct methods and refined using the Rietveld method. Significant distortions of the ZrO6 and MoO4 polyhedral elements are observed for δ-ZrMo2O8, as compared to the ambient conditions of the α-phase, while the packing of anions becomes more symmetric at high pressure.