Theory of elastic phase transitions in metals at high pressures. Application to vanadium

Structural transformations in elementary metals under high pressures are considered using the Landau theory of phase transitions, in which the finite strain tensor components play the role of the order parameter. As an example, the phase transition in vanadium observed at a pressure of 69 GPa is analyzed. It is shown that it is a first-order elastic phase transition, which is close to a second-order transition.