论文部分内容阅读
利用多种方法观察了弛豫型铁电单晶ＰＭＮＴ中电畴结构随组分与结构的演变过程与特征．观察发现，在ＰＭＮ－ＰＴ的三方相区内，随ＰＴ含量的增加，电畴结构表现出微畴一（亚微畴）－不规则宏畴一规则宏畴转变历程；在三方－四方相变中，非１８０°电畴发生７１°（或１０９°）宏畴－９０°宏畴的转化，同时电畴图像变得更为规则．根据不同组分ＰＭＮＴ电畴的显示特征，提出晶体的最大双折射率可以作为度量其弛豫性强弱的光学参数．观察到了电畴的分布不均匀与多级结构现象，前者与组分或结构的起伏有关，后者与多期式马氏体转变有关．本文还分析了偏光显微镜、ＤＩＣ、ＳＥＭ、ＳＥＡＭ等观察方法中电畴的成像特征．
A variety of methods were used to observe the evolution and characteristics of domain structure with composition and structure of the relaxed ferroelectric single-crystal PMNTs. It was found that in the three-phase region of PMN-PT, with the increase of the content of PT, the domain structure of the domains showed a domain transition of micro-domain one (submicroscopic domain) -orregular macro-domain; in the case of three-phase-tetragonal phase transition In the non-180 ° domain, a 71 ° (or 109 °) domain of macro-domain-90 ° domain transition occurs, and the domain image becomes more regular. According to the display characteristics of the different components of the PMNT domain, the maximum birefringence of the crystal can be used as an optical parameter to measure its relaxation strength. The phenomenon of heterogeneity of distribution and multistage structure was observed. The former is related to the fluctuation of composition or structure, the latter is related to multi-period martensitic transformation. This paper also analyzes the imaging features of the domains in the observation methods of polarization microscope, DIC, SEM and SEAM.