Raman study of temperature‐induced phase transitions in lead hafnate (PbHfO 3 )

Results of a high‐temperature Raman spectroscopic investigation up to 522 K carried out at ambient pressure on an antiferroelectric PbHfO 3 multi‐domain single crystal are reported. The changes in the Raman spectral features show that temperature‐induced phase transitions occur at 435 ± 1 and at 484 ± 1 K. The first transition is possibly to a tetragonal structure and the second is to the cubic perovskite phase. The behavior is consistent with the earlier x‐ray study of PbHfO 3 . No soft mode behavior associated with the transitions was detected in the Raman spectra of PbHfO 3 . The changes observed in the high‐temperature Raman spectra of PbHfO 3 are similar to those found in the spectra of isostructural PbZrO 3 .