Raman spectra of BaTiO3 and Ce: BaTiO3 single crystals have been recorded between room temperature and 180℃. Three new bands at 986,1204 and 1480 cm-1 in the X(ZZ) Y geometry are discovered. Based upon the temperature dependence of Raman scattering cross sections, the new bands are attributed to the second-order Raman spectra of BaTiO3, while the strong asymmetry bands at 275 and 514 cm-1 in A1(TO) spectrum are confirmed to be of first order. On the basis of above results, the Raman spectra of cubic BaTiO3 and the model of phase transitions are discussed. It is found that doping with Ce in BaTiO3 lowers its Curie temperature, which agrees with the experimental results of dielectric constants.
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