Co_2O_3掺杂对0.965MgTiO_3-0.035SrTiO_3微波介质陶瓷性能的影响

采用传统电子陶瓷制备方法研究了Co2O3(1.5%～5.0%,质量分数)掺杂的0.965MgTiO3-0.035SrTiO3(MST0.035)微波介质陶瓷,分析了Co2O3含量对MST0.035陶瓷的烧结性能、晶相结构、显微形貌以及微波介电性能的影响。结果表明:Co2O3的掺杂促进了MST0.035陶瓷的烧结。随着Co2O3掺杂量的增加,陶瓷介电常数略有下降,谐振频率温度系数以及品质因数增加,同时中间相MgTi2O5逐渐减少直至完全消失。当Co2O3掺杂量为质量分数3.0%时,MST0.035陶瓷的烧结温度由1 380℃降低到1 290℃,其烧结所得的样品具有优良的微波介电性能:谐振频率温度系数τf=–2.53×10–6/℃,高的品质因数Q·f=19 006 GHz和介电常数εr=20.5。

Effect of Co2O3 dopant on the properties of 0.965MgTiO3-0.035SrTiO3 microwave dielectric ceramic

0.965MgTiO3-0.035SrTiO3(MST0.035)microwave dielectric ceramics doped with Co2O3(1.5%～5.0%,mass fraction) were prepared by traditional electronic ceramic technique,the influences of Co2O3 content on sintering characteristics,phase compositions,microstructures and microwave dielectric properties of MST0.035 microwave ceramics were studied.The results indicate that the sintering degree of MST0.035 ceramic is promoted by doping Co2O3.The permittivities of ceramics decrease slightly,temperature coefficient of resonant frequency and quality factor of the ceramics increase,the mesophase MgTi2O5 diffraction peak decreases gradually to disappear completely with the increase of Co2O3 dopant.As the addition of Co2O3 is 3.0%(mass fraction),the sintering temperature of MST0.035 ceramic reduces from 1380 ℃ to 1 290 ℃.The sintered sample exhibits excellent microwave dielectric properties: temperature coefficient of resonant frequency τf=–2.53×10–6/℃,high quality factor Q·f =19006 GHz and permittivity εr = 20.5.