Raman scattering and phase transitions in stressed SrTiO₃

Application of a [111] uniaxial stress to the low-temperature phase of strontium titanate is found to shift the frequency of the lowest two Raman-active modes. Comparison with a phenomenological theory shows that the results support other evidence for a stress-induced tetragonal-to-trigonal phase transition. Application of stress in the [110] direction produced no evidence of a phase change. © 1971.