(Na_(0.5)Bi_(0.5))TiO_3陶瓷A位二价金属离子取代的研究

Investigation on Substitution of Divalent Metallic Ion for A Site in (Na_(0.5)Bi_(0.5))TiO_3

主要研究了用Ｂａ２＋、Ｓｒ２＋、Ｃａ２＋对钙钛矿结构（ＡＢＯ３）的无铅压电陶瓷（Ｎａ０．４Ｂｉ０．５）ＴｉＯ３（ＮＢＴ）的Ａ位 进行部分取代后材料的介电、压电性能。实验表明，Ａ位Ｂａ２＋取代使ＮＢＴ的介电系数有明显的增大，而Ｓｒ２＋、Ｃａ２＋ 对ＮＢＴ的介电系数影响不大。而３种离子Ａ位的取代，都使ＮＢＴ的高矫顽电场有了大幅度的降低，其中以Ｂａ２＋的 效果最为明显（２． ５～２． ０ ｋＶ／ｍｍ）；但随着 Ｅｅ的降低，材料的 Ｐｒ值也同步降低。

This paper investigated the effects of partial substitution of three kinds of divalence metallic ion (Ba2+ 、Sr2+、.Ca2+ ) for A site in (Na0.5Bi0.5 ) TiO3 on the dielectric and piezoelectric properties of this lead-free ceramics with perovskite structure. Introduction of Ba2+ leads to an increase of dielectric constant,while that of Sr2+ and Ca2+ don't. Ee value decreases sharply with substitution in A site as well as the remanent polarization Pr