Sb_2O_3掺杂Zn-Nb-O基微波介质陶瓷的结构与性能

Structure and Dielectric Properties of Sb_2O_3 Doped Zn-Nb-O Based Microwave Ceramics

采用传统电子陶瓷工艺制备(ZnNb2O6-Zn3Nb2O8)-Sb2O3(ZZS)陶瓷,研究了Sb2O3含量对ZZS陶瓷结构及介电性能的影响规律。结果表明,Sb2O3的加入促进了陶瓷的烧结,陶瓷中除ZnNb2O6和Zn3Nb2O8两种主晶相外未有新相生成,Sb2O3则以Sb3+或Sb5+置换Nb5+/Zn2+形成置换固溶体;陶瓷的介电常数(εr)随Sb2O3含量的增加先增大后减小,保持在23～25之间,介电损耗略有增加。微波频段下,0.7ZnNb2O6-0.3Zn3Nb2O8陶瓷的介电常数随Sb2O3含量的增加略有减小,品质因数与频率的乘积(Q×f)值先增大后减小。当w(Sb2O3)=1%时,陶瓷综合性能最佳,εr=22.88,Q×f=38 871GHz。

（ZnNb2 O6-Zn3 Nb2O8 ）-Sb2O3 （ZZS） ceramics were fabricated by the conventional ceramic processing. The effects of the contents of Sb2O3 on the microstructures and dielectric properties of ZZS ceramics were investigated. The results showed that Sb2O3 accelerated the sintering of ZnNb2 O6-Zn3 Nb2O8 ceramics. No other phase was observed in the ceramics except the two main phases of ZnNb2O6 and Zn3Nb2O8. It was shown that Sb3＋ could change into Sb5＋ and replace Nb5＋ or Zn2＋ to form the substitutional solid solution. The dielectric constant （εr） increased firstly and then decreased with the increase of the content of Sb2O3, but maintained between 23 and 25, while the dielectric loss has increased slightly. At the microwave frequency range, the dielectric constant of 0.7ZnNb2O6- 0.3Zn3Nb2O8 decreased slightly and the value of Q× f increased firstly and then decreased with the content of Sb2 O3. The ceramic with the composition of 1 % of Sb2O3 showed the optimal dielectric properties of εr = 22.88 and Q×f=38 871 GHz.