中文摘要：

BSTO铁电陶瓷材料的介电常数随外加直流偏压的变化呈现非线性特性。纯BSTO材料由于较高的介电常数和较大的介电损耗不能满足移相器介质材料的要求，通过在BSTO中添加Bi2O3来改善BSTO铁电陶瓷材料的介电性能。结果表明：（1）在BSTO体系中微量掺杂Bi2O3，Bi^3＋以取代Ba^2＋的方式存在于钙钛矿的晶格中，形成均匀的固溶体Ba0.5-xBixSr0.5TiO3;（2）随Bin添加量的增加，居里峰逐渐变宽，峰高逐渐降低，相变弥散效应增强；（3）Bi^3＋的掺杂能细化晶粒，并显著降低BSTO体系的介电常数。

英文摘要：

BaxSr1-xTiO3 [（BSTO）, 0≤x≤ 1] is a solid solution ferroelectric material exhibiting a large dielectric constant non-linear change with an applied dc electric field. Pure BSTO can not satisfy the requirements of phase shifter due to its high dielectric constants and losses It has been shown that the dielectric constants and losses of barium strontium titanate can be reduced by doping certain oxides. In this paper, we present systematic studies of the effect of Bi2O3 doping on BSTO bulk ceramics. The results showed that： （1） By adding Bi203 into BSTO bulk ceramics, Bi^3＋ substitute for Ba^2＋ cation sites at A position of ABO3 perovskite structure to form homogeneous solid solution; （2） With the increase of Bi2O3-doping content, ferroelectric-paraelectric transition peaks become broadened, the maximum permittivity value decreases and dispersion phase transition effect is enhanced; （3） Proper quantity of Bi2O3 could reduce the grain size and dielectric constants of BSTO ceramics significantly.