BaAl2-2xZn2xSi2O8陶瓷结构与微波介电性能研究

Ceramic structure and microwave dielectric properties of BaAl2-2xZn2xSi2O8

采用固相烧结法,按化学计量比合成了BaAl2-2xZn2xSi2O8(x=0,0.25%,0.5%,0.75%,1%,1.5%)陶瓷。研究了不同Zn^2+掺杂量对BaAl2Si2O8(BAS)系微波介质陶瓷晶体结构和介电性能的影响。结果表明:Zn^2+取代Al3+产生氧空位可以有效促进BAS由六方相转变为单斜相,将BAS陶瓷的烧结温度降低至1350℃,并改善BAS陶瓷样品的密度、品质因数(Q×f)及谐振频率温度系数(τf)。当x=0.75%,烧结温度为1350℃时,可获得综合介电性能较好的BAS陶瓷,其介电性能为:εr=6.67,Q×f=46226 GHz,τf=-25.21×10^-6/℃。

BaAl2-2xZn2xSi2O8(x=0,0.25%,0.5%,0.75%,1%,1.5%)ceramics were synthesized by solid state sintering method.The effects of Zn^2+dopant concentration on the crystal structure and dielectric properties of BaAl2Si2O8(BAS)microwave dielectric ceramics were investigated.The results show that the O2-vacancies,due to Zn^2+substitution of Al3+,can effectively promote the transformation of BAS from hexagonal to monoclinic phase,which reduces the sintering temperature to 1350℃and improves parameters such as the density,quality factor(Q×f)and temperature coefficient of resonant frequency(τf).BAS ceramics with optimized dielectric properties can be obtained when x=0.75%and sintering temperature is 1350℃.The optimized dielectric parameters areεr=6.67,Q×f=46226 GHz,τf=-25.21×10^-6/℃.