Elastic properties of crystals below the point of ferroelastic phase transition with a multicomponent order parameter

Abstract

Tensors of averaged strains and elastic moduli are calculated for the ideal plane-parallel twin structure. The components of the averaged tensors are expressed through the twinning elements. Elastic properties of the twin structure arising below the point of ferroelastic phase transition are described. The cases of cubic-to-tetragonal and cubic-to-rhombohedral phase transitions are considered in details. It is shown that in both cases the structure of the tensor of averaged elastic modula coincides with that of a monoclinic single crystal.

Key Words:

• Twin structure
• thermoelastic phase transition
• elastic moduli