Raman spectroscopy study of phase transitions in lead magnoniobate-titanate crystals

The Raman spectra of (1 - {chi})Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-{chi}PbTiO{sub 3} crystals have been studied at {chi} = 0.2 within the temperature range 120-700 K. It was established that the first-order Raman spectrum of the cubic phase is associated with local structural distortions and occurred at {Tau} < 480 K. The intensity of the high-frequency band was shown to exhibit anomalies at the points of transition to the class (355 K) and rhombohedral (324 K) phases. 15 refs., 3 figs.