title: Electronic structure and phase transition in ferroelectic Sn(2)P(2)S(6) crystal.
abstract: An analysis of the P2S6 cluster electronic structure and its comparison with the crystal valence band in the paraelectric and ferroelectric phases has been done by first-principles calculations for Sn2P2S6 ferroelectrics. The origin of ferroelectricity has been outlined. It was established that the spontaneous polarization follows from the stereochemical activity of the electron lone pair of tin cations, which is determined by hybridization with P2S6 molecular orbitals. The chemical bonds covalence increase and rearrangement are related to the valence band changes at transition from the paraelectric phase to the ferroelectric phase.
authors.affiliation: Institute for Solid State Physics and Chemistry, Uzhgorod National University, Voloshyn Street 54, Uzhgorod 88000, Ukraine. kglukhov@gmail.com.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Glukhov
authors.forename: Kristina
authors.initials: K
authors.lastname: Fedyo
authors.forename: Juras
authors.initials: J
authors.lastname: Banys
authors.forename: Yulian
authors.initials: Y
authors.lastname: Vysochanskii
mesh_terms: D008956:Models, Chemical; D044367:Phase Transition