ZBAS对BaAl2Si2O8结构与微波介电性能的影响

采用固相反应工艺, 按化学计量百分比BaAl₂Si₂O₈-x(ZnO-Al₂O₃-SiO₂-B₂O₃)(x=0, 1%, 2%, 3%, 4%)制备样品, 研究了不同含量ZnO-Al₂O₃-SiO₂-B₂O₃(ZBAS)玻璃相对BaO-Al₂O₃-SiO₂系介电材料显微结构及微波介电性能的影响。结果表明: 添加ZBAS玻璃相可以适当降低烧结温度, 促进六方钡长石转变为单斜钡长石。当x≥3%时, 六方钡长石可以完全转变为单斜钡长石。随着ZBAS玻璃相含量的增多, 样品的密度、介电常数(ε_r)、品质因数(Q×f)和谐振频率温度系数(τ_f )增大。在x=3%, 烧结温度为1360℃时, 可以获得综合性能相对较好的单斜钡长石, 其介电性能: ε_r=6.72, Q×f=28058 GHz, τ_f =-29.79×10^-6℃^-1。

ZBAS on the Structure and Dielectric Property of BaAl2Si2O8

Barium feldspar BaO-Al₂O₃-SiO₂ system materials have been studied widely for satellite communication, microwave substrate and packaging in recent years. BaAl₂Si₂O₈-x(ZnO-Al₂O₃-SiO₂-B₂O₃) (x=0, 1%, 2%, 3%, 4%) ceramics were prepared by solid state route. The effects of ZBAS glass on the sintering behaviour, phase composition and microwave dielectric properties of BaAl₂Si₂O₈ were investigated. Addition of ZBAS glass can effectirely lower the sintering temperature to 1360℃ without changing phase composition of the sample and greatly propel the transition from hexacelisian to celsian. When x≥2%, the transition from hexacelisian to celsian reaches 100%. Density, dielectric constant and τ_f of BaAl₂Si₂O₈-ZBAS ceramics increase with the increment of ZBAS glass in the range of 1%≤x≤4%. In addition, the resonant frequency temperature coefficient is negative. The BaAl₂Si₂O₈-ZBAS sintered at 1360℃ obtains a high Q×f of 28058 GHz, ε_r=6.72 and τ_f=-29.79×10^-6℃^-1 at x=3%. Deviations between experimental and theoretical relative permittivity of BaAl₂Si₂O₈-xZBAS is also discussed.