Complex Aggregative Multi-Minima Models for Ferroelastic Transitions in Crystals

Abstract

The specific features of the thermodynamics of the crystals with particles situated in potential wells of different depths are considered in the framework of 1 + 4 minima model. The deepest central well in it is surrounded by four lateral wells which comprise the set of the equivalent crystallographic positions. We show that in such crystals the isostructural phase transitions and strong anomalies in the absence of transition can appear. Also the ordered phase can emerge without the local stability loss of the initial one.

Keywords:

• Multi-minima models
• order-disorder phase transitions
• thermodynamic properties