随着光电子学的发展,纳米材料正起着越来越重要的作用.近来的理论研究表明,纳米尺寸的半导体微晶具有较高的三阶非线性极化率和快速响应速度.因此,纳米材料的研究十分活跃.但由于多元化学组成和很高的结晶温度,采用普通的工艺以及气相冷凝的方法难于得到纳米尺寸的铁电粒子.然而,体材料中纳米相的研究可以追溯到50年代,Kanzig在纯净的BaTiO_3中观察到了环境温度高于Curie温度时存在着尺寸为10～100nm的极性微区.这种极性微区现在称为Kanzig微区.后来,扩散相变的研究、微畴-宏畴转变的研究等都采用了这一概念. With the development of optoelectronics, nanomaterials are playing more and more important roles.Recent theoretical studies show that nanocrystalline semiconductor crystallites have high third-order nonlinear polarizabilities and fast response speeds, However, the study of nanomaterials in bulk materials can be traced back to the 1950s due to the diversity of chemical compositions and high crystallization temperatures, which are difficult to obtain by conventional techniques and vapor phase condensation , Kanzig observed in pure BaTiO_3 the ambient temperature is higher than the Curie temperature when there is a size of 10 ~ 100nm polar region.The polar region is now called the Kanzig micro-region.Afterward, the study of the diffusion phase transition, Micro-domain - the study of macro-domain changes have adopted this concept.