纳米钛酸钡陶瓷的特殊烧结方法和新颖特性的研究进展

New Sintering Method and Novel Characteristics of Nanocrystalline BaTiO_3 Ceramics

对近年来有关纳米钛酸钡陶瓷最新的烧结方法、新颖性质进行了综合评述和讨论。当晶粒尺寸减小到纳米尺度时,钛酸钡陶瓷的晶体结构在不同的温度下出现了不同的多相共存。这可以用纳米钛酸钡陶瓷相变产生的应力来解释。纳米钛酸钡陶瓷的铁电性能表现出新颖的特性。它的介电常数先随晶粒尺寸的减小而降低,但当晶粒尺寸降低到小于50 nm甚至小于10 nm时,介电常数表现出反常的增加,同时铁电向顺电的转变峰变为一个很宽的峰,表现出弥散相变的特征。

The new sintering method and novel properties of nanocrystalline BaTiO3 ceramics are introduced. When particle size is reduced to the nanoscale, there are multiphase coexistences in nanocrystalline BaTiO3 ceramics. It can be explained by the internal stress. The dielectric behavior of nanocrystalline BaTiO3 ceramics reveals the novel characteristics. The dielectric constant first decreases with reducing the grain size, while the grain size is reduced to be- low 50nm and even below 10nm, it increases abnormally. The dielectric peak is characterized by the broadened ferroe- lectric-to-paraelectric phase transition which exhibits the characteristic of diffuse phase transition.