Polarization reversal anti-parallel to the applied electric field observed using a scanning nonlinear dielectric microscopy

Anti-parallel poling reversal phenomenon was observed using a nonlinear dielectric microscope. This poling reversal was unexpected because the poling direction was aligned anti-parallel to the applied electric field. This was only detected for thicker films with the critical thickness in the case of lithium tantalate film being about 350 nm. In thinner films, only normal poling reversal was observed. Normal polarization reversal was observed as the applied voltage increased and anti-parallel polarization reversal was observed during the falling edge.