High-pressure theoretical and experimental study of HgWO₄

Abstract

HgWO₄ at ambient pressure is characterized using a combination of ab initio calculations, X-ray diffraction and Raman scattering measurements. The effect of low pressure and temperature on the structural stability is analysed. Extending our ab initio study to the range of higher pressures, a sequence of stable phases up to 30 GPa is proposed.

Keywords:

• phase transitions
• tungstates
• ab initio calculations
• Raman scattering
• X-ray diffraction

Acknowledgements

We thank J.M. Menéndez for his help in the use of the GIBBS code. This work has been supported by the Spanish MEC under Projects MAT2007-65990-C03-01/03, MAT2010-21270-C04-03/04 and CSD-2007-00045 and by the “Vicerrectorado de Innovación y Desarrollo de la UPV” (PAID-05-2009 through project UPV2010-0096). We gratefully acknowledge computational time provided by the “Red Española de Supercomputación” at the supercomputer “Atlante”. S.R. acknowledges financial support from the “Vicerrectorado de Investigación de la UPV” through grant PAID-02-09-3085.