Peculiarities of the pT-diagram in the ferroelastic transformation in CsDy(MoO4)2

The ''temperature-external single-axis pressure'' diagram of CsDy (MoO4)2 monocrystal that has a segnetoelectric transition of the first kind at the temperature Tsub(k) approximately 38 K, is investigated. The effect of single axis pressure on the structural transition in studied by optic methods. Electron spectra of CsDy (MoO4)2 in the range of phase transformation in the case of temperature and pressure alteration are given. The reduced temperature-single axis compression diagram in presented. It in shown that in the definite temperature range the splitting of CsDy(MoO4)2 monocrystal into layers into existing phases in observed. Pressure increase with fixed temperature brings about the ''duffusing'' in the temperature of the phase transition on the basis of which the conclusion in made by authors on the existence of critical pressure at which the disappearance of the transition takes place