Domain structure evolution near ferroelastic-superionic phase transition in CsDSO4 crystals

Ferroelastic domain structure with (013),(032),(0 (3) over bar 2),(0 (1) ov er bar 3) domain walls is induced in (100) cut of CsDSO4 crystals by compre ssion at room temperature. This domain pattern as well as domain picture ar ising near superionic phase transition in (010) and (100) samples are in ag reement of cubic symmetry of a hypothetical prototype phase. The performed studies proved that about 3-4 K below the superionic phase there occurs a p hase transition. This is in good agreement with theoretical assumptions. Th e domain structure and character of its variations are similar of polidomai n structure of a martensite.