复合添加剂掺杂对CLST微波介质陶瓷性能的影响研究

STUDY ON THE EFFECT OF COMPOSITE ADDITIVE ON THE CLST MICROWAVE DIELECTRIC CERAMICS

采用传统电子陶瓷制备工艺,以Li2CO3-B2O3-SiO2-CaO-Al2O(3LBSCA)玻璃料42BaO-45B2O3-13SiO2(BBS)玻璃料和Na2CO3为复合烧结助剂,制备了可以中温烧结的Ca0.3(Li1/2Sm1/2)0.7TiO3(CLST)陶瓷,对其晶相组成、烧结性能及微波介电性能进行了系统研究。结果表明:通过液相烧结,复合烧结助剂能有效降低CLST陶瓷的烧结温度,由1300℃降低至950～1000℃。XRD结果显示陶瓷主晶相为斜方钙钛矿,没有发现杂相。添加复合烧结助剂比单独添加一种烧结助剂更能降低陶瓷的烧结温度,但陶瓷的微波介电性能略有下降。添加5wt%LBSCA,12.5wt%BBS和2.5wt%Na2CO3复合烧结助剂的CLST陶瓷在950℃保温5h烧结时具有较好的微波介电性能:εr=57.56,Qf=1338GHz,τf=59.72ppm/℃。

Ca0.3（Li1/2Sm1/2）0.7TiO3（CLST） ceramics were fabricated via traditional ceramic process at a median sintering temperature using Li2CO3-B2O3-SiO2-CaO-Al2O3 （LBSCA）glass42BaO-45B2O3-13SiO2（BBS） glass and Na2CO3 as composite sintering additive. The crystal structure, sintering behavior, and microwave dielectric properties of CLST ceramics were investigated systematically. The results indicate that the composite sintering additive can effectively decrease the sintering temperature of CLST from 1300 ℃ to 950- 1000℃ by liquid phase sintering. The major phase of CLST ceramics is orthorhombic perovskite and no second phases were found by XRD analysis. The degree of decreasing sintering temperature for the CLST ceramic with composite sintering additive is better than that with a single additive, but the microwave dielectric properties decreased. The sample of CLST with 5wt% LBSCA, 12.5wt% BBS and 2.5wt%Na2CO3 sintered at 950℃ for 5h has good dielectric properties： εr = 57.56, Qf = 1338GHz, τf =59.72ppm/℃.