Monte-Carlo simulations of the phase transitions in the Rb₂ZnCl₄ crystal

Abstract

The model of the order- disorder phase transitions in Rb₂ZnCl₄ is studied. In this model BX₄ , group has a four equlibrium orientations in a disordered hexagonal phase. The constants of the interaction between orderinq BX₄ groups are calculated in the framework of the electrostatic model. It is shown that these constants have a competitive nature. The Monte-Carlo method is applied to study the successive phase transitions hexagonal ⇒ orthorombic ⇒ incommensurate ⇒ commensurate ferroelecrtic phases.