Title: p,T,E-DIAGRAM OF n_2P_2S_6 FERROELECTRIC WITH HIGH-PRESSURE INCOMMENSURATE PHASE
Author(s): V.M.Kedyulich, A.G.Slivka, E.I.Gerzanich, V.S.Shusta (Uzhgorod State University, 34 Voloshin Str., 294000 Uzhgorod, Ukraine)

The investigations on the temperature change in dielectric permeability of Sn$_2$P$_2$S$_6$ crystal at different misaligning electric fields and hydrostatic pressures have been carried out to establish the form of $p,T,E$-diagram for this crystal. Based on the investigations on dielectric permeability anomalies, the $E,T$-diagrams at different magnitudes of hydrostatic pressure and $p,T,E$-diagram of Sn$_2$P$_2$S$_6$ crystal have been constructed. The magnitudes of coefficients in the thermodynamic potential expansion have been estimated and coordinates of critical points in $E,T$-diagrams have been defined.

Comments: Figs. 3, Refs. 5, Tabs. 0.