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

• Published in: Scientific reports Vol. 14; no. 1; pp. 7106 - 8
• Main Authors: Margaritescu, Irina, Liu, Zenghui, Ye, Zuo-Guang, Mihailova, Boriana
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/2795; 639/766/119/996; Crystals; Energy; Ferroelectrics; High temperature; Humanities and Social Sciences; multidisciplinary; Phase transitions; Pressure; Science; Science (multidisciplinary); Single crystals; Solid solutions; Temperature
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-57765-w

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 temperature and pressure evolution of the fraction of the local non-tetragonal polar distortions is highly sensitive to the type of B-site substituent.