Ab initio study of the high-pressure phases and dynamical properties of ZnAl₂O₄ and ZnGa₂O₄

Abstract

In this paper, we report ab initio calculations of the vibrational and structural properties of ZnAl₂O₄ and ZnGa₂O₄ spinel structures. The calculated vibrational modes at zero pressure, at the Γ point and the complete phonon spectrum of both compounds are presented. Also, we report our findings for the high-pressure structure dependences of spinel and post-spinel structures.

Keywords:

• ab initio
• phase transition
• phonon spectrum
• spinel structure

Acknowledgements

A.H.R. and S.L. have been supported by CONACyT Mexico under projects J-59853-F and J-83247-F. P. R.-H. and A.M. acknowledge the financial support of the MICINN of Spain under grant nos. MAT2007-65990-C03-03 and CSD2007-00045. We also thank the computer resources provided by MareNostrum, Spain and CNS, Ipicyt, México.