MgO-Al2O3-SiO2-B2O3对BaAl2Si2O8结构与微波介电性能的影响

摘要

BaAl2 Si2O8-x( MgO-Al2O3-SiO2-B2O3 ) ( x=0％, 1％, 2％, 3％, 4％, mass fraction) ceramics were prepared by solid state route. The crystal structure and microwave dielectric properties of BaO-Al2 O3-SiO2 with different MgO-Al2O3-SiO2-B2O3 ( MBAS) glass contents were studied by automatic density meter, XRD and network analyzer. The results show that MBAS glass can greatly promote the phase transition of BaAl2 Si2O8 from hexacelisian to celsian. The transition can reach 100％ when x≥2％. With the increasing of MBAS glass content, the density, relative permittivity andτf of BaAl2 Si2 O8-MBAS ceramics increase. The BaAl2 Si2 O8-x (MBAS) sintered at 1410 ℃ shows a high Q·f of 35644 GHz, εr of 6.02 andτf of -26. 2×10-6℃-1 at x=2％.%采用固相反应工艺,制备了BaAl2 Si2O8-x(MgO-Al2 O3-SiO2-B2O3)(x=0％,1％,2％,3％,4％,质量分数)微波介质陶瓷.通过密度仪、XRD、 网络分析仪等设备研究不同含量MgO-Al2 O3-SiO2-B2O3(MBAS)玻璃相对BaO-Al2 O3-SiO2(BAS)系介电材料结构及微波介电性能的影响.结果表明:MBAS玻璃相能有效促进六方钡长石转变为单斜钡长石,当x≥2％时,可以得到100％转变的单斜钡长石.随着MBAS玻璃相含量的增多,样品的密度、 相对介电常数(εr)、 品质因数(Q·f)和谐振频率温度系数(τf)增大.在x=2％,烧结温度为1410℃时,可获得综合性能相对较好的单斜钡长石,其介电性能:εr=6.02,Q·f=35644 GHz,τf=-26.2×10-6℃-1.