SrCO3掺杂对BMT陶瓷结构及介电性能的影响

Effects of SrCO_3 Dosages on Structure and Dielectric Properties of BMT Ceramics

采用固相烧结法制备SrCO3掺杂Ba(Mg1/3Ta2/3)O3(BMT)微波介质陶瓷,研究SrCO3质量(下同)掺量w(SrCO3)=2%～8%对BMT微波介质陶瓷结构和介电性能的影响。结果表明:添加适量SrCO3可以促进烧结并在一定程度上提高BMT陶瓷体系的B位离子1:2有序度;当w(SrCO3)=6%时,陶瓷致密化烧结温度由纯相时的1650℃以上降至1500℃,体积密度ρV=7.534g/cm3,相对密度达到98.7%,此时陶瓷体系获得良好的微波介电性能:相对介电常数εr=24.5,品质因数与谐振频率的乘积Q.f=99000GHz(8GHz),谐振频率温度系数τf=9.6×10-6℃-1。

Microwave dielectric ceramics of SrCO3 doped Ba（Mg1/3Ta2/3）O3 （BMT） were prepared using solid state reaction. Effects of SrCO3 on structure and microwave dielectric properties of BMT ceramic were investigated as a function of SrCO3 mass fraction （the same below） from 2% to 8%. It is found that sinterability of the BMT can be improved greatly and B-site ordering degree increases to a certain extent with adding the appropriate amount of SrCO3 . In comparison with pure BMT ceramics, the BMT ceramic doped with 6% SrCO3 shows a lower sintering temperature decreasing from 1650 ℃ to1500 ℃. Its bulk density ρV= 7.534g/cm3 , and relative density is 98.7%. The BMT demonstrates the best microwave dielectric properties： relative dielectric constant ε r=24.5, quality factor plus resonant frequency Q·f=99 000 GHz （8 GHz,）, and temperature coefficient of resonant frequency τ f=9.6×10–6 ℃–1