ZnO–B2O3掺杂BaAl2Si2O8陶瓷的结构及微波介电性能

Structure and Microwave Dielectric Properties of ZnO–B2O3 Doped BaAl2Si2O8

采用固相反应法制备BaAl2Si2O8–x%ZnO–B2O3(x=0,1,2,3,4,质量分数)陶瓷。探究了不同含量的ZnO–B2O3(ZB)烧结助剂对BaAl2Si2O8(BAS)陶瓷的烧结温度、结构及微波介电性能的影响。结果表明:ZB烧结助剂可降低BAS陶瓷的烧结温度。并且能够促进BAS晶体结构由六方相转变为单斜相,当x=1时,六方相BAS全部转变为单斜相BAS,并且ZB烧结助剂添加量在4%以内,无第二相生成。添加1%的ZB烧结助剂可促进样品晶粒长大,密度、介电常数和品质因数增大,谐振频率温度系数的绝对值减小。在x=1,烧结温度为1 350℃时,能够获得品质因数较高的单斜相BAS,其介电性能为:εr=6.45,Q×f=40 608 GHz,τf=–22.46×10^–6 K^–1。

BaAl2Si2O8 ceramics with a samll amount of ZnO–B2O3(ZB)as sintering additives were prepared by solid-state sintering.The sintering temperature,structure and microwave dielectric properties of BaAl2Si2O8(BAS)with ZB were investigated.The results show that the ZB sintering additives can reduce the sintering temperature and promote the transition of crystal structure of BAS.As x=1,all the hexacelsian transforms into celsian,and the second phase does not appear as x≤4.The sintering additives of 1% ZB can promote the grain growth,increase the bulk density,dielectric constant and Q×f value,and decrease the absolute value of τf.The BAS with 1% ZB sintered at 1 350℃shows a high Q×f of 40 608 GHz,and the dielectric properties are εr=6.45 and τf=–22.46×10^–6 K^–1.