The role of local non-tetragonal polar displacements in the temperature- and pressure-induced phase transitions in PbTiO₃-BiMeO₃ ferroelectrics.

ABSTRACT: In situ high-pressure/high-temperature Raman-scattering analyses on PbTiO 3 , 0.92PbTiO 3- 0.08Bi(Zn 0.5 Ti 0.5 )O 3 and 0.83PbTiO 3- 0.17Bi(Mg 0.5 Ti 0.5 )O 3 single crystals reveal an intensity transfer between the fine-structure components of the A 1 (TO) soft mode. The enhancement of the lowest-energy subpeak, which stems from intrinsic local non-tetragonal polar distortions, along with the suppression of the tetragonal A 1 (1TO) fundamental mode with increasing pressure and temperature indicates the key role of the local polarization fluctuations in transformation processes and emphasizes the significance of the order-disorder phenomena in both the pressure- and temperature-induced phase transitions of pure PbTiO 3 and its solid solutions with complex perovskites. Moreover, the temper

SUBMITTER: Margaritescu I 

PROVIDER: S-EPMC11349899 | biostudies-literature | 2024 Mar

REPOSITORIES: biostudies-literature