不同方式引入CuO制备低温烧结(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7陶瓷

Preparation of low-temperature sintered(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramics doped by CuO in different methods

以Bi2O3、ZnO和Nb2O5为原料,采用传统固相反应法制备(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7（BZN）陶瓷。通过Cu O包覆层修饰BZN粉体表面,引入Cu O助烧剂代替直接混合BZN和Cu O粉体。以CuSO4溶液为先驱体制备CuO包覆层,采用液相包覆法引入助烧剂可减少CuO的添加量,从而降低Cu O对BZN陶瓷介电性能的不良影响。结果表明,当Cu SO4溶液浓度为0.5mol/L时,可以促进陶瓷的烧结和致密化过程,经900℃烧结3h所得BZN陶瓷介电性能最佳,介电常数（εr）为141,品质因数值（Qf）为426 GHz,谐振频率温度系数（τf）为-357×10-6/℃（4 GHz）,皆优于固相混合法所得介电性能(介电常数为134,品质因数为287 GHz,谐振频率温度系数为-374×10-6/℃（4 GHz）)。

(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7（BZN） ceramics were synthesized by the traditional solid-state reaction method, using Bi2O, Zn O, and Nb2O5 powders as raw materials. The surface of BZN powders was modified by CuO coating layer, and the CuO sintering aid was introduced instead of directly mixing BZN and CuO powders. The CuO coating layer was prepared with CuSO4 solution as the precursor solution, and the addition of CuO could be reduced by using liquid coating method, thereby reducing the negative impact of CuO on the dielectric properties of BZN ceramics. The results show that, in liquid coating method, when the concentration of CuSO4 solution is 0.5 mol/L, the sintering and densification process of BZN ceramics can be promoted. The optimal dielectric properties of BZN ceramics are obtained by sintering for 3 h at 900 ℃, the dielectric constant is 141, the quality factor is 426 GHz, and the temperature coefficient of resonance frequency is-357×10-6/℃（4 GHz）, which are much better than those obtained by solid-phase mixing method, that is to say, the dielectric constant is 134, the quality factor is 287 GHz, and the temperature coefficient of resonance frequency is-374×10-6/℃（4 GHz）.