Domains and domain wall interactions near the improper ferroelastic phase transition of KSCN

In the present paper the authors study the evolution of the ferroelastic domains and domain wall interactions of KSCN with temperature using a polarizing microscope. The typical lens shape of the ferroelastic domains in KSCN and the change of their shape (i.e. the width and length) with temperature are explained in terms of the dislocation theory for twin boundaries. The interface between the high- and low-symmetry phases was found to be at 45 degrees orientation with respect to the ferroelastic domain walls, in agreement with recent theoretical results.