Dispersive effects and correction term in two-mode phonon conduction model for Ge Original Research Article

Raman spectra of Ba6−3xSm8+2xTi18O54 solid solution were investigated as the function of x and sintering time. Reasonable explanations were provided about the Raman shifts and their intensities at 1013, 590, 751, 280, 232 cm−1. 1013 cm−1 demonstrates the existence of BaCO3 phase in solid solution, 590 cm−1 is the symmetric stretching mode of the basal oxygens of the octahedral; 280 and 232 cm−1 are the symmetric stretching modes resulted from the tilt of octahedral when large cation sites are Sm3+ and Ba2+. The shoulder peak appearing around 302 cm−1 is related to the vacancy produced by the unequal valence of Sm3+ and Ba2+.