添加LCB玻璃的CSLST微波介质陶瓷低温烧结及其性能研究

采用传统电子陶瓷工艺制备了添加Li2CO3-CuO-B2O3(LCB)玻璃为烧结助剂的(Ca0.9375Sr0.0625)0.3(Li0.5Sm0.5)0.7TiO3(CSLST)微波介质陶瓷,并对其烧结特性、晶相组成和介电性能进行了系统的研究。结果表明:通过液相烧结,LCB玻璃能有效降低CSLST烧结温度至900℃。XRD分析结果显示添加LCB玻璃后材料中均产生了杂相。性能分析结果发现随着LCB添加量的增大,陶瓷的体积密度、介电常数εr、品质因数与谐振频率乘积Q×f呈现先上升后下降的趋势,频率温度系数τf则单调降低。添加质量分数为12.5%的LCB玻璃的CSLST陶瓷在900℃下保温5 h可以完全烧结,并具有最佳的微波介电性能:εr=77.7,Q×f=1845 GHz,τf=21.35×10-6/℃。

Research on Low-temperature Sintering and Dielectric Properties of CSLST Microwave Ceramics Doped with LCB Glass

Microwave dielectric ceramics(Ca0.9375Sr0.0625)0.3(Li0.5Sm0.5)0.7TiO3(CSLST) doped with Li2CO3-CuO-B2O3(LCB) glass as sintering additive were prepared by the conventional electronic ceramic processing technology.The sintering behavior,crystal phase structure and dielectric properties were investigated systematically.The results indicated that LCB glass could effectively decreased the sintering temperature of CSLST to 900 ℃ by liquid phase sintering.But some other phases were found by XRD analysis.As the LCB content increasing,the bulk density,the dielectric constant(εr),product of quality factor and resonance frequency(Q×f) values of CSLST ceramic all increased firstly and then decreased.But the temperature coefficient of the resonance frequency(τf) decreased monotonously.The sample of CSLST with 12.5wt% LCB sintered at 900 ℃ for 5 h has the best microwave dielectric properties:εr=77.7,Q×f=1845 GHz,τf=21.35×10-6 /℃.