Bi_(1.5+x)Zn_(1.0)Nb_(1.5)O_(7+1.5x)(x=0.075,0.15)陶瓷的结构和介电性能

Structures and Dielectric Properties of Bi_(1.5+x)Zn_(1.0)Nb_(1.5)O_(7+1.5x)(x=0.075,0.15) Ceramics

采用固相反应法,以立方焦绿石Bi_(1.5)Zn_(1.0)Nb_(1.5)O_7(BZN)为配方基础,通过改变Bi^(3+)离子与O^(2-)离子的浓度,形成非化学计量比Bi_(1.5+x)ZN_(1.0)Nb_(1.5)O_(7+1.5x)(x=0.075,0.15)陶瓷。研究了不同Bi含量和烧结温度对BZN陶瓷的结构、微观形貌以及介电性能的影响。结果表明制备的非化学计量比BZN陶瓷在不高于1050℃时,呈现焦绿石单相结构;随着烧结温度增加到1100℃,x=0.075,出现ZnO杂相;x=0.15,出现Bi_2O_3杂相。随着x值的增大,BZN陶瓷样品的晶格常数、密度以及介电常数都逐渐增加。

The conventional solid-state reaction technology was adopted. Based on the Bi_1.5Zn_1.0Nb_1.5O7 formula, the non- stoichiometric pyrochlore ceramics were prepared by changing the concentration of Bi^3＋ and O^2-. The ceramic with the formula Bi_（1.5＋x）Zn_1.0Nb_1.5 O_（7＋1.5x）（x=0.075,0.15） were investigated. The effects of excessive Bi amount and sintering temperature on structure, morphology and dielectric properties of BZN ceramics were also discussed. It can be found that the prepared non-stoichiometric ceramics have a pure cubic pyrochlore structure, when sintered below 1050℃. As the sintering temperature increases to 1100℃, x=0.075, the ZnO impurity phase appears. However, when x=0.15, the Bi2O3 impurity phase appears. And with the increase of x value, the lattice constant, density and dielectric constant of BZN ceramics gradually increase.