On the paraelectric phase structure of AB′_xB″_1−xO₃-type compounds

Abstract

Our Raman scattering studies demonstrate that the paraelectric phase in a number of AB′ _x B″_1−x O₃-type compounds with a “diffuse phase transition” into ferroelectric phase turns out not to be a simple perovskite structure as it has been considered. The Raman scattering appears to be rather sensitive to the change of a space symmetry, so that we could suggest a nontrivial sequence of phase transitions instead of the adopted conception on an exceptional type of “diffuse phase transition”. Therefore one can consider these preceding phases as precursor ones.