Li_(1．0)Nb_(0．6)Ti_(0．5)O_3陶瓷的低温烧结及其微波介电性能

Low Temperature Sintering and Microwave Dielectric Properties of Li_(1.0)Nb_(0.6)Ti_(0.5)O_3 Ceramics

研究了以Li1．0Nb0．6Ti0．5O3(LNT)陶瓷为基体, B2O3-ZnO-La2O3(BZL)玻璃为烧结助剂的复合材料的低温烧结行为及微波介电特性．研究表明,BZL玻璃能有效降低LNT陶瓷的烧结温度,掺入10wt％BZL玻璃的复合材料能够在900℃烧结致密．XRD与SEM分析结果表明,添加BZL玻璃的样品烧结后含有LNT和LaNbTiO6两种晶相,其中LaNbTiO6相是LNT与BZL玻璃在烧结过程中发生化学反应的产物．在LNT陶瓷中添加BZL玻璃使材料的介电常数和品质因数下降,但有助于减小体系的谐振频率温度系数．掺入10wt％BZL玻璃的复合材料在900℃烧结2h后获得了比较满意的微波介电特性:介电常数k≈58,品质因数Q×f≈4800GHz,谐振频率温度系数τf≈11×10-6／℃．

Li1.0Nb0.6Ti0.5O3 （LNT） ceramics were prepared at 900℃ by adding B2O3-ZnO-La2O3 （BLZ） glass as sintering agent, and the densification process and the microwave dielectric properties of the material were investigated. The results show that the BLZ glass can effectively decrease the sintering temperature of the material. Beside the main crystal phase Li1.0Nb0.6Ti0.5O3, LaNbTiO6 is found in the material, which is believed to be the product of the reaction between LNT and BZL glass during sintering. Adding BZL glass to LNT ceramics leads to the decrease of dielectric constant k and the quality factor Q × f of the material, but at the same time, helps to improve the temperature coefficient of resonant frequency Tf. The low firing Li1.0Nb0.6Ti0.5O3 ceramic is possessed with k ≈ 8, Q × f ≈4800GHz and Tf≈ 11× 10^-6/℃.