Raman study of an electric-field-induced phase transition in Pb(Zn_1/3Nb_2/3)O_3-8%PbTiO_3

Abstract

Electric-field-induced structural transition of a single crystal Pb(Zn1/3Nb2/3)O3-8%PbTiO3 grown in the (001) direction was studied by use of Raman scattering spectroscopy. By comparing the changes in Raman spectra induced by the electric field with the temperature-dependent changes, we could confirm that the structural transition to tetragonal phase is initiated at a threshold electric field Ec1 and completed at higher transition field Ec2. In the electric-field range from Ec1 to Ec2, it is found that rhombohedral and tetragonal phases coexist. The lower threshold field Ec1 is found to coincide with the field at which the strain rises abruptly in the strain electric-field hysteresis loop while the upper threshold field Ec2 corresponds to the electric field where a slope change is observed in the high-field saturation region beyond the hysteresis loop.