BCL助烧剂对CSLST微波介质陶瓷性能的影响

采用B2O3-CuO-Li2CO3(BCL)作为助烧剂对(Ca0.9375Sr0.0625)0.3(Li0.5Sm0.5)0.7TiO3(CSLST)微波介质陶瓷进行降温烧结。系统讨论了BCL的添加量对CSLST微波介质陶瓷的烧结行为、晶体结构及微波介电性能的影响。结果表明:BCL的加入将CSLST陶瓷的烧结温度从1 250℃降至925℃。当BCL添加量小于质量分数5.5%时,样品中只含单一的钙钛矿结构晶体,而当BCL添加量大于质量分数7.5%时,则会产生第二相。添加BCL的质量分数为5.5%,烧结温度为925℃保温5 h,所制CSLST陶瓷具有良好的微波介电性能:εr=86.69,Q.f=2 267 GHz,τf=29.3×10–6/℃。

Effects of BCL sintering additives on the properties of CSLST microwave dielectric ceramics

B2O3-CuO-Li2CO3(BCL) sintering additive was used to lower the sintering temperature of(Ca0.9375Sr0.0625)0.3(Li0.5Sm0.5)0.7TiO3(CSLST) ceramics.The effects of BCL doping amount on the sintering behavior,crystal structure and microwave dielectric properties of CSLST microwave dielectric ceramics were discussed.The results show that BCL can effectively decrease the sintering temperature of prepared ceramics from 1 250 ℃ to 925 ℃.XRD analyses indicate that no second phase can be detected when the BCL doping amount is less than 5.5%(mass fraction),while the second phase appeares when the BCL doping amount is over 7.5%(mass fraction).The ceramics with 5.5%(mass fraction) BCL doping sintered at 925 ℃ for 5 h possess optimized microwave dielectric properties: εr=86.69,Q·f = 2 267 GHz,τf=29.3×10–6/℃.