Li2O-Na2O-B2O3-SiO2烧结助剂对BaAl2Si2O8陶瓷结构与介电性能的影响  

Effect of Li2O-Na2O-B2O3-SiO2 Sintering Aids on the Structure and Dielectric Properties of BaAl2Si2O8 Ceramics

作　　者：严欣堪 丁士华[1] 张晓云 黄龙 张云 YAN Xin-Kan;DING Shi-Hua;ZHANG Xiao-Yun;HUANG Long;ZHANG Yun(School of Materials Science and Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学材料科学与工程学院

出　　处：《无机化学学报》2019年第8期1357-1362,共6页Chinese Journal of Inorganic Chemistry

基　　金：教育部春晖计划项目(No.Z2011077);四川省特种材料及制备技术重点实验室开放课题资助项目(No.szjj2017-059)

摘　　要：采用传统固相反应工艺,按化学计量比合成BaO-Al2O3-SiO2 (BAS)-x%(w/w) Li2O-Na2O-B2O3-SiO2 (LNBS)(x=0,1,2,3,4)陶瓷。研究不同LNBS烧结助剂添加量对BAS系微波介质陶瓷的结构和介电性能的影响。通过Clausius-Mossotti公式计算讨论了BAS理论与实验介电常数(εr)的差异。研究结果表明:LNBS烧结助剂中Li^+进入钡长石Al^3+位或单四元环(S4R)间隙,并产生了O2-空位或Ba^2+空位,从而促进BAS六方相向单斜相的转变。添加适量的LNBS烧结助剂后,BAS陶瓷的烧结温度从1 400 ℃降低到1 325 ℃,同时BAS陶瓷样品密度、品质因数(Qf)值以及频率温度系数(τf)得到改善。当x=1,烧结温度为1 325 ℃时,可获得综合性能相对较好的BAS陶瓷,其介电性能:Qf=35 199 GHz,εr=6.37,τf=-1.613×10^-5 ℃^-1。BaO-Al2O3-SiO2 (BAS)-x%(w/w) Li2O-Na2O-B2O3-SiO2 (LNBS)(x=0,1,2,3,4) ceramics were prepared by solid state route.The effect of LNBS sintering aids on the microstructure and dielectric properties of BAS system ceramics were studied.Deviation between theoretical and experimental permittivity (εr) of BAS was discussed.The results showed that LNBS sintering aids could reduce the sintering temperature from 1 400 to 1 325 ℃,and the O2- vacancy or Ba^2+ were formed by Li^+ substituting for Al3^+ or Li^+ entering into the single four-membered-ring (S4R) to promote the transformation of hexacelsian to celsian of BAS.The density,quality factor (Qf) value,the temperature coefficient of resonant frequency (τf) of BAS-x% LNBS ceramics have been improved by adding moderate LNBS sintering aids.The BAS-1% LNBS sintered at 1 325 ℃ obtained well dielectric properties: Qf=35 199 GHz,εr=6.37 and τf=-1.613×10^-5 ℃^-1.

关 键 词：LNBS烧结助剂 BaAl2Si2O8 单斜相 微波介电性能 

分 类 号：TQ174[化学工程—陶瓷工业]