Raman spectra of Ba6−3xSm8+2xTi18O54 solid solution

Raman spectra of Ba_6−3xSm_8+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⁺.