Low frequency shear compliance of the ferroelastic crystal calomel

Abstract

The low frequency mechanical properties of the improper ferroelastic Hg₂Cl₂ have been investigated with a torque-twist setup. In contrast to standard methods in the investigation of elastic constants this technique is very sensitive to defect structures. Two anomalies are observed, one in the critical regime of the phase transition, the other at low temperatures. We ascribe these effects to stress induced motion of domain walls, their proliferation and partial freezing of their mobility.

Key Words:

• Hg₂Cl₂
• domain wall freezing
• domain mobility
• low frequency shear compliance