非化学计量比对(Mg_(0.95)Zn_(0.05))_(1+δ)TiO_(3+δ)陶瓷的显微结构和微波介电性能的影响

Effect of Non-stoichiometry on Microstructure and Microwave Dielectric Properties of(Mg_(0.95)Zn_(0.05))_(1+δ)TiO_(3+δ) Ceramics

针对MgTiO_(3)微波介质陶瓷存在烧结后容易产生第二相,且损耗较大等问题,本文在掺杂Zn^(2+)的同时采用非化学计量比的条件下,对(Mg_(0.95)Zn_(0.05))_(1+δ)TiO_(3+δ)(-0.1≤δ≤0.3)陶瓷的显微结构和微波介电性能进行研究。结果表明:非化学计量比的改变对材料的介电常数和谐振频率温度系数影响不大,却能很大程度上改变品质因数Qf。(Mg_(0.95)Zn_(0.05))_(1+δ)TiO_(3+δ)陶瓷在0≤δ≤0.2的很大范围内保持了MgTiO_(3)单相,且在1365℃烧结下,获得了最大的品质因数Qf=166000 GHz,此时,相对介电常数ε=16.5,谐振频率温度系数τ=-37.2×10^(-6)℃^(-1)。相对于纯MgTiO_(3)陶瓷,品质因数明显提高。

In order to solve the problems that the second phase was produced after sintered and the loss was large for MgTiO_(3)microwave dielectric ceramics,the microstructure and microwave dielectric properties of(Mg_(0.95)Zn_(0.05))_(1+δ)TiO_(3+δ)(-0.1≤δ≤0.3)ceramics were studied by doped Znand nonstoichiometric ratio.The results show that the dielectric constant and resonant frequency temperature coefficient of materials are not affected by the change of nonstoichiometric ratio,but the quality factorQfcan be greatly changed.(MgZn)TiOceramics keep the MgTiO_(3)single phase in a wide range of 0≤δ≤0.2,and obtain the maximum quality factorQf=166000 GHz when sintered at 1365℃.The dielectric constantε=16.5.The resonant frequency temperature coefficientτ=-37.2×10^(-6)℃^(-1).Compared with pure MgTiO_(3)ceramics,the quality factor is obviously improved.