Comments on the hysteresis loop in ferroelastic LiCsSO₄

Abstract

Recent experiments on LiCsSO₄ revealed a single stress-strain hysteresis loop for samples cut along the x-direction, and a double hysteresis loop for samples cut along the y-direction. In this paper we propose a Landau-based free-energy expansion which gives a qualitative explanation of the phenomenon. We also discuss the reasons why the observed curve is smooth and not rectangular as the simple theoretical model would imply.