准同型相界组分PMNT弛豫铁电单晶的畴结构与极化特性

Study on Domain Morphology and Polarizing Characteristics of PMNT Relaxor Ferroelectric Single Crystal

采用坩埚下降法生长了具有准同型相界(MPB)组分的65Pb(Mg1/3Nb2/3)O3-35PbTiO3(PMNT65/35)弛豫铁电单晶。用偏光显微镜研究了(001)、(110)和(111)三个结晶学取向的铁电畴结构,观察到明暗交替的变化。通过对极化前后电畴形状的比较,分析了极化前后铁电畴形态的变化原因。晶片极化条件为:600V/mm的电场并保持10～15min。研究了极化介质不同对极化后晶片压电性能的影响。

65Pb（Mg1/3Nb2/3）O3-35PbTiO3（PMNT65/35） single crystals with morphotropic phase boundaries （MPB） composition between the rhombohedral and tetragonal phase regions were grown by the Bridgman method. Electric domains on （001）, （110） and （111） surfaces were observed by the polarizing microscope. The samples were polarized under 600 V/mm for 10-15 min and the domain morphology were discussed before and after polarizing. The influence of polarizing conditions on piezoelectric constants studied also.