Acta Crystallographica Section B

Structural Science

Volume 57, Part 1 (February 2001)

research papers

Acta Cryst. (2001). B57, 20-26 [ doi:10.1107/S0108768100013215 ]

High-pressure structures of - and -ZrMo₂O₈

A. M. Krogh Andersen and S. Carlson

Abstract: In situ high-pressure synchrotron X-ray powder diffraction studies of trigonal [alpha] -ZrMo₂O₈, zirconium molybdate, have been performed from ambient conditions to 1.9 GPa, over the [alpha] - [delta] phase transition at 1.06-1.11 GPa. The monoclinic structure of [delta] -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 [delta] -ZrMo₂O₈, as compared to the ambient conditions of the [alpha] -phase, while the packing of anions becomes more symmetric at high pressure.

Keywords: high-pressure diffraction; distortion; framework structures.