Ferroelastic phase transitions in Csr(MoO4)2-CsR(WO4)2 with R = Dy, Ho, Er, Tm, Yb, and Lu

The phase transitions, phase S-T diagrams and domain structure in CsR(MoO4)2 - CsR(WO4)2 system of crystals were studied. The phase transitions were found to be displacement structural phase transitions, attended by a jump of the dielectric constant and formation of ferroelastic domains.