Pressure-induced phase transition in PbSc0.5Ta0.5O3 as a model Pb-based perovksite-type relaxor ferroelectric.
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.
Mihailova
B
B
Mineralogisch-Petrographisches Institut, Universität Hamburg, Grindelallee 48, 20146 Hamburg, Germany. mi0a007@uni-hamburg.de
Angel
R J
RJ
Welsch
A-M
AM
Zhao
J
J
Engel
J
J
Paulmann
C
C
Gospodinov
M
M
Ahsbahs
H
H
Stosch
R
R
Güttler
B
B
Bismayer
U
U