title: Pressure-induced phase transition in PbSc0.5Ta0.5O3 as a model Pb-based perovksite-type relaxor ferroelectric.
abstract: We report pressure-induced structural changes in PbSc(0.5)Ta(0.5)O3 studied by single-crystal x-ray diffraction and Raman scattering. The appearance of a soft mode, a change in the volume compressibility, broadening of the diffraction peaks, and suppression of the x-ray diffuse scattering show that a phase transition occurs near pc approximately 1.9 GPa. The critical pressure is associated with a decoupling of the displacements of the B site and Pb cations in the existing polar nanoregions, leading to the suppression of B-cation off-center shifts and enhancement of the ferroic distortion in the Pb-O system.
authors.affiliation: Mineralogisch-Petrographisches Institut, Universität Hamburg, Grindelallee 48, 20146 Hamburg, Germany. mi0a007@uni-hamburg.de
authors.forename: B
authors.initials: B
authors.lastname: Mihailova
authors.forename: R J
authors.initials: RJ
authors.lastname: Angel
authors.forename: A-M
authors.initials: AM
authors.lastname: Welsch
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: J
authors.initials: J
authors.lastname: Engel
authors.forename: C
authors.initials: C
authors.lastname: Paulmann
authors.forename: M
authors.initials: M
authors.lastname: Gospodinov
authors.forename: H
authors.initials: H
authors.lastname: Ahsbahs
authors.forename: R
authors.initials: R
authors.lastname: Stosch
authors.forename: B
authors.initials: B
authors.lastname: Güttler
authors.forename: U
authors.initials: U
authors.lastname: Bismayer