Effects of Electric Field on Domain Configurationin the [100]_(cub)-oriented Crystal of PMN-PT

The domain configuration in the cub-oriented crystal of relaxor-ferroelectric PMN-PT was investigated with a polarizing microscope.The results indicated that under the positive DC electric field,the small ribbon-like domains paralleling to the electric field disappeared gradually when the intensity of electric field exceeded 2.45 kV/cm,and the new domains perpendicular to the electric field emerged near the electrode when the intensity of electric field rose to 7.15 kV/cm.Under the negative DC electric field,the ribbon-like domains grew along the electric field when the intensity of electric field exceeded 2.05 kV/cm.When the intensity of electric field reached 7.15 kV/cm,the domains paralleling to the electric field disappeared gradually and the new domains perpendicular to the electric field emerged.Under AC electric field,domains were vibrating with the frequency less than 50 Hz.