低温烧结微波介质陶瓷（1－x）Ba3（VO4）2-xLi2 MoO4的微波性能研究

采用固相反应制备了（1－x）Ba3（VO4）2-xLi2MoO4微波介质陶瓷，研究了掺入不同质量比的Li2MoO4对Ba3（VO4）2的微观结构和微波介质性能影响，X线衍射（XRD）测试结果表明，Ba3（VO4）2和Li2MoO4二者兼容性良好，无第二相产生。添加具有低熔点及相反（负）频率温度系数的Li2 MoO4能有效降低Ba3（ VO4）2的烧结温度，并随着添加剂Li2 MoO4的增加，此复合陶瓷的相对体密度、介电常数εr 和品质因数Q ×f呈现出先增加随后又降低的趋势，而谐振频率里面温度系数τf逐渐降低。当烧结温度为660℃且添加量30wt％Li2 MoO4的复合微波介质陶瓷获得了最佳的微波介电性能：εr ＝11．99， Q ×f＝39700 GHz，τf ＝－24 ppm／℃。

Microwave Properties of(1-x) Ba3 (VO4) 2-xLi2 MoO4 Microwave Dielectric Ceramics Sintered at Low Temperature

The(1-x) Ba3 ( VO4 ) 2-xLi2 MoO4 ceramics have been prepared by the conventional soli-state reaction method , the effects of different mass ratio of Li 2 MoO4 on the microstructures and microwave dielectric properties of Ba3(VO4)2 are studied.The X-ray diffraction (XRD)test results indicated that Ba3(VO4)2 and Li2MoO4 phase coexist in the composite,and no secondary phases can be detected .The sintering temperature of Ba 3 ( VO4 ) 2 could be reduced with low melting point and negative temperature coefficient Li2 MoO4 .The relative density, dielectric constant and quality factor Q ×f of the compound ceramics all increase firstly and then decrease with the increase of the amount of the Li 2 MoO4 addition , however , the temperature coefficient of resonant frequency τf decreases gradually .The density of the microwave dielectric ceramics with 0.3 Li2 MoO4 addition sintered at 660 ℃ can reach the excellent microwave dielectric properties with εr=11.99,Q ×f=39700 GHz,τf=-24 ppm/℃.