中文摘要：

采用偏光显微镜观察了电场作用下[100]cub切型PMN-PT弛豫铁电单晶电畴组态的变化.结果表明：在正向电场作用下,当电场强度超过2.45 kV/cm时,平行于电场方向小畴条带慢慢消失,当电场强度升高到7.15 kV/cm时,原畴壁逐渐消失,在接近电极附近试样上优先出现了垂直于电场方向的新电畴;在反向电场作用下,电场强度超过2.05 kV/cm时,电畴条带沿电场方向扩展,当电场强度升到7.15 kV/cm时,平行于电场方向电畴消失,而出现许多垂直于电场方向电畴;在交流电场驱动下,电畴以低于50 Hz的频率做周期性振动.

英文摘要：

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.