Structural transformations at high pressure in the refractory metals (Ta, Mo, V)

Abstract

In the framework of the Landau theory, the elastic phase transitions under pressure in metals with a cubic lattice are considered. The model of such transitions is proposed. Conditions for the loss of stability of a cubic crystal under hydrostatic pressure are obtained. The effective elastic constants of second, third and forth orders and phonon dispersion of V, Mo and Ta in wide range of pressure were calculated by the density functional theory. The stability of bcc lattice and structural transformations in these metals are investigated on base of the obtained data. © 2012 Elsevier B.V. All rights reserved.