【摘要】 采用固相烧结法制备Ba(Mg_1/3Nb_2/3)O₃+x（x=0⁸）%SnO₂（BMSN,x为质量分数）微波介质陶瓷,并研究SnO₂掺杂对Ba(Mg_1/3Nb_2/3)O₃（BMN）微波介质陶瓷结构及介电性能的影响。XRD分析表明,陶瓷体系中存在两种相,主晶相Ba(Mg_1/3-Nb_2/3)O₃和附加相Ba₅Nb₄O₁₅。随着x的增大,BMSN陶瓷体系的相结构逐渐由钙钛矿六方结构转变为立方结构,同时有序相逐渐由1∶2有序结构转变为1∶1有序结构。研究表明:添加适量的SnO₂可以促进液相烧结,当SnO₂掺杂质量分数为6%时,BMN陶瓷致密化烧结温度由纯相时的1 550℃以上降低至1 200℃,表观密度ρ=6.39g/cm3,相对理论密度为99.1%,此时BMSN陶瓷体系拥有优良的微波介电性能——高相对介电常数（ε_r=33.6）,接近于零的谐振频率温度系数(τ_f=0.15×10^-6℃^-1),高品质因数与谐振频率的乘积（Q·f=112 300GHz（8GHz））。更多还原

【Abstract】 The structure and microwave dielectric properties of Ba(Mg_1/3Nb_2/3)O₃（BMN）ceramics doped with x（x=0-8）wt% SnO₂（BMSN）were investigated by the solid-state reaction technique.XRD analysis suggested there were two phases:main crystalline phase Ba(Mg_1/3Nb_2/3)O₃ and secondary phase Ba₅Nb₄O₁₅.As xvalue increased,the crystal structure changed from perovskite hexagonal structure to cubic structure and the ordered phase changed from 1∶2 ordered structure to 1∶1 ordered structure.It was found that the liquid phase sintering can be promoted greatly by adding an appropriate amount of SnO₂.When 6wt% SnO₂ was added,the BMN ceramic showed a lower sintering temperature（1 550℃）compared to pure BMN（1 200℃）,an apparent densityρof 6.39g/cm³,a relative theoretical density of 99.1%,also excellent microwave dielectric properties:high relative dielectric constant（ε_r= 33.6）,near-zero temperature coefficient of resonant frequency valueτf=0.15×10^-6℃^-1,high quality factor plus resonant frequency（Q·f=112 300GHz（8GHz））.更多还原