APPEARANCE OF PARAELASTIC PHASE AS FERROELASTIC DOMAIN-WALLS IN K2CD2(SO4)(3) SINGLE-CRYSTALS

Domain-phase boundaries of K2Cd2(SO4)(3) were observed under a polariz ation microscope at the ferroelastic phase transition region. The expe riment revealed that a heterophase structure with ''forbidden'' domain walls appeared and a paraelastic phase layer played the role of the d omain walls. The orientation and thicknesses of the domain-phase walls were experimentally determined to be {110} and 16 similar to 45 mu m, respectively. The origin of the heterophase structure is discussed ph enomenologically based on the assumed prototype phase with paint group (4) over bar 3 m.