Raman Study of Ba0.7Ca0.23TiO3Single Crystals

In the present work we report on Raman study of Ba0.77Ca0.23TiO3 crystals in the temperature region between 12 K–300 K. We believed to gain insight on the role of Ca admixture, and search manifestations of the possible low temperature tetragonal-orthorhombic phase transition. A special attention was paid to the temperature evolution of A1 and E components of the Γ15 modes. Signatures of the presence of CaTiO3 modes are evidenced at around 100 cm−1. The Raman data give no clear indications of the soft mode driven low temperature phase transitions presence, at least down to 12 K, revealing, however, increasing of disordering at cooling.