Electric-field-induced structural transition of a single crystal $\mathrm{Pb}\left({\mathrm{Zn}}_{1/3}{\mathrm{Nb}}_{2/3}\right){\mathrm{O}}_3-8\%{\mathrm{PbTiO}}_3$ 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 $E_{c1\mathrm{}}$ and completed at higher transition field $E_{c2\mathrm{}}.$ In the electric-field range from $E_{c1\mathrm{}}$ to $E_{c2\mathrm{}},$ it is found that rhombohedral and tetragonal phases coexist. The lower threshold field $E_{c1\mathrm{}}$ 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 $E_{c2\mathrm{}}$ corresponds to the electric field where a slope change is observed in the high-field saturation region beyond the hysteresis loop.

• Received 12 October 2000

DOI:https://doi.org/10.1103/PhysRevB.64.094105