Nonlinear dielectric response in the relaxor Pb(Mg1/3Nb2/3)O-3 single crystal

The temperature dependence of the third-order nonlinear dielectric constant and the time dependence of the linear dielectric constant under a step DC field in a typical relaxer, Pb(Mg1/3Nb2/3)O-3 single crystal, were measured around the temperature where the dielectric constant shows a maximum value . It was found that the nonlinear dielectric constant shows a broad peak wi thout any indication of divergence. It was also found that the dielectric c onstant under the step DC field changes slowly with time. The nonlinear res ponse of relaxer ferroelectrics was discussed.