Phase diagram of the relaxor (1 - x)Pb(Zn_(1/3)Nb_(2/3))O_(3-.x)PbTiO_3 investigated by dielectric and Raman spectroscopies

摘要

Lead zinc niobate-lead titanate[(1 - x)Pb(Zn_(1/3)Nb_(2/3))O_(3-x)PbTiO_3] (PZN-PT) crystals with x = 4.5% and x = 12% have been investigated using dielectric and Raman measurements over a range of temperatures. Above room temperature, dielectric measurements show that both compositions exhibit structural phase transitions according to the phase diagram proposed by Kuwata et al. [Ferroelectrics 387 (1981) 579]. Below room temperature, an anomaly at around 180 K for the x = 12% sample is observed, suggesting another phase transition. Raman measurements are used to study all phase transitions.