Abstract
Dielectric, optical, pyroelectric properties of (PbxSn1−x)2P2Se6 ferroelectric solid solutions in the region of phase transitions are studied under high hydrostatic pressure. The p,Tx phase diagram of (PbxSn1−x)2P2Se6 crystal is constructed. The peculiarities of physical properties of these material in the incommensurate phase region are investigated.