Influence of electric field and domain structure on the low-temperature Raman spectra of SrTiO₃

The domain structure of SrTiO₃ below its cubic to tetragonal phase transition depends not only on the stress-state of a particular sample but can also be modified very efficiently by the application of electric fields. Hence, the interpretation of field induced phenomena needs a careful consideration of the domain distribution which is often neglected in existing studies. In this paper, it is shown that the strong variation of polarized Raman spectra under external fields observed within both the paraelectric tetragonal phase and the field induced ferroelectric phase, is a direct consequence of the redistribution of domains. Raman data can therefore be used to characterize the domain structure of a particular sample. (paper)