Electric-field-induced polarization in the ergodic and nonergodic states of PbMg1/3Nb2/3O3 relaxor

We report results obtained from polarization measurements on ${\mathrm{PbMg}}_{\mathrm{1/3}}{\mathrm{Nb}}_{\mathrm{2/3}}{\mathrm{O}}_{\mathrm{3}}$ single crystal under static electric field, in both field cooling and field switching after zero field cooling processes. In the field cooling process, two kinds of regime are observed depending on the field strength, i.e., above and below threshold value $E_t\text{≈1.7\hspace{0.05em}}\mathrm{kV/cm}.$ From the low field regime results we have extracted both linear and nonlinear susceptibilities, which exhibit an anomaly close to the freezing temperature. In the field switching after zero field cooling experiments, a local polarization corresponding to the appearance of polar nuclei develops up to a critical value where the nuclei collapse into macroscopic ferroelectric macrodomains.