CaWO_4-Li_2WO_4陶瓷低温烧结特性及微波性能研究

Low-temperature Sintering and Microwave Dielectric Properties of CaWO_4-Li_2WO_4 Ceramics

采用固相反应法制备了(1-x)CaWO4-xLi2WO4(0≤x≤0.14)微波陶瓷,研究了Li2WO4作为第二相对CaWO4微波陶瓷的低温烧结特性和微波性能的影响。结果表明,Li2WO4相的存在能明显降低CaWO4的烧结温度,并且随着x的增加,(1-x)CaWO4-xLi2WO4(0≤x≤0.14)陶瓷体系的最佳烧结温度降低。当x=0.1,在900℃下烧结2h,该陶瓷材料的介电常数εr=9.002,品质因数与频率之积Q×f=11.76×104 GHz,谐振频率温度系数τf=-55×10-6/℃。在此基础上采用w(CaTiO3)=5.0%调节其谐振频率温度系数到0,调节后的微波介电性能为εr=10.312,Q×f=5.36×104 GHz。

The （1-x） CaWO4-xLi2 WO4 （0≤x≤0.14） microwave ceramics were prepared by the solid state re- action method. The effect of Li2WO4 as second phase on the low-temperature sintering and microwave dielectric properties of CaWO4 was investigated. The results showed that the existing LizWO4 phase can reduce the sintering temperature of CaWO4 significantly; furthermore, with x increase, the optimal sintering temperature of （1-x） Ca- WO4-xLizW04 （O≤x≤O. 14） ceramic system decreased. At x：0. 1, the （1-x） CaWO4-xLizW04 ceramics sin- tered at 900 ℃ for 2 h presented excellent microwave dielectric properties. The dielectric constant of cr is 9. 002, the Q X f is 11.76 X 104 GHz and the temperature coefficient of resonant frequency of rl is --55 × 10^6/℃. On this ba- s is,w （CaTiO3） = 5.0 % was used to adjust the temperature coefficient of resonant frequency to zero. The micro- wave dielectric properties after adjusting was εr = 10. 312 ,QX f = 5.36 × 104 GHz and rsvp.0.