Ba(Mg1/3Nb2/3)O3-Mg4Nb2O9复相陶瓷微波介电性能研究

Study on Microwave Dielectric Properties of Ba(Mg1/3Nb2/3)O3-Mg4Nb2O9 Composite Ceramics

采用传统固相法制备了(1-x)Ba(Mg1/3Nb2/3)O3-xMg4Nb2O9[(1-x)BMN-xM4N2,x=0.003~0.125]微波介质陶瓷,研究了相结构、烧结性能与介电性能随x的变化规律。结果表明:BMN与M4N2可以两相共存,且二者间存在有限固溶,BMN的烧结温度及高温稳定性有所降低。随着x的增大,介电常数εr和谐振频率温度系数τf逐渐减小,Q×f值的变化易受到BMN有序参数S的影响,高度1:2有序的x=0.026陶瓷获得了最大Q×f值125000 GHz。综合来看,在1320℃下保温4 h烧结的x=0.125样品表现出最佳的微波介电性能:εr=26.6,Q×f=111000 GHz,τf=5 ppm/℃。

In this paper,(1-x)Ba(Mg1/3Nb2/3)O3-xMg4Nb2O9[(1-x)BMN-xM4N2,x=0.003~0.125]microwave dielectric ceramics were prepared by the traditional solid-phase method.The phase structure,sintering behavior and dielectric properties were studied.The results showed that:BMN and M4N2couldcoexist,and few amount of them could form limited solid-solution.The sintering temperature and thermal stability of BMN decreased.With the increase of x,dielectric constantεr and the temperature coefficient of resonance frequencyτf of composite ceramics gradually decreased,the change of Q×f values was easily affected by the ordering parameter S of BMN.The highly 1:2 ordered x=0.026 ceramics obtained the maximum Q×f value of 125000 GHz.On the whole,the sample with x=0.125 sintered at 1320℃for 4 h showed optimum microwave dielectric properties:εr=26.6,Q×f=111000 GHz,τf=5 ppm/℃.