Polarization rotation contributions to dielectric nonlinearity in 65Pb(Mg1/3Nb2/3)O3-35PbTiO3 single crystals

The dielectric response of 65Pb(Mg1/3Nb2/3)O-3-35PbTiO(3) (PMN-35PT) single crystals is reported for ac field amplitudes up to similar to 3.5 kV/cm over a frequency range from 3 Hz to 1 kHz. The nonlinear dielectric response is described by a Rayleigh-like analysis, indicating extrinsic contributions from nonlinear and hysteretic motion of internal interfaces (phase boundaries and domain walls). Furthermore, the extrinsic contributions are more than five times higher in the [110]- and [001]-poled crystals than crystals poled along the [111] axis. This is attributed to the ease of the polarization vector rotation along the M-C mirror plane between orthorhombic and tetragonal phases of PMN-35PT.