Microwave Properties in BaO-TiO sub(2) System Added by ZrO sub(2) and WO sub(3)

Both BaTi sub(4)O sub(9) and Ba sub(2)Ti sub(9)O sub(20) have the best microwave properties among many compounds in BaO-TiO sub(2) system. The microwave performance of the ceramics in BaO-TiO sub(2) system, which were prepared by conventional solid state method, was investigated in this paper. The study indicates that the (Ti,Zr)/Ba ratio has a great effect on the dielectric properties of the ceramic due to different BaTi sub(4)O sub(9)/Ba sub( 2)Ti sub(9)O sub(20) ratio. The pure BaTi sub(4)O sub(9) ceramic exhibits the most outstanding microwave properties, with epsilon sub(r)=35.55 and Qxf=43300GHz. On the contrary, the dielectric property of the pure Ba sub(2)Ti sub(9)O sub(20) ceramic was not good enough, which should be doped with some additive additions. WO sub(3) was incorporated into the system and the sintering temperature was adjusted to improve the microwave dielectric property. The Qxf was increased to 38000GHz by adding 1.35mol% WO sub(3) due to the formation of a little BaWO sub(4) phase. When sintered at a higher temperature (1380[degrees]C), the BaO-TiO sub(2) system ceramic has epsilon sub(r) =37.04 and Qxf =44874GHz.