Co取代对Nd(Zn0.5Ti0.5)O3微波介质陶瓷结构与性能的影响

采用传统固相法制备Nd[（Zn1-xCox）0.5Ti0.5]O3（0≤x≤0.9）微波介质陶瓷,研究Co^2＋在B位取代Zn^2＋对Nd（Zn0.5Ti0.5）O3微波介质陶瓷的结构和微波介电性能的影响.结果表明,在研究的组分范围内,Nd[（Zn1-xCox）0.5Ti0.5]O3陶瓷均能形成单斜钙钛矿型固溶体,随Co取代量增加,陶瓷的相对介电常数er逐渐减小,谐振频率温度系数tf逐渐向负值移动,品质因数Q×f先增大后下降,在x=0.3 mol时达到最大值215130 GHz,Q×f大幅增加是有序度作用所致.在1410℃下烧结4 h,Nd[（Zn0.7Co0.3）0.5Ti0.5]O3陶瓷具有优异的微波介电性能,ετ=31.2,Q×f=215 130 GHz,η=-35.7×10^-6℃^-1.

Sintering characteristics and microwave dielectric properties of 0.5Ca_(0.6)La_(0.267)TiO_3-0.5Ca(Mg_(1/3)Nb_(2/3))O_3 ceramics prepared by reaction-sintering process

0.5 Ca（0.6La0.267TiO3-0.5 Ca（Mg1/3Nb2/3）O3（5 CLT-5 CMN） ceramics were prepared by a reaction-sintering process and their sintering characteristics, microwave dielectric properties were investigated in detail.Without any calcination stage involved,a mixture of CaCO_3, La_2 O_3, TiO_2, MgO and Nb_2 O_5 was pressed and sintered directly. Pure phase 5 CLT-5 CMN ceramics with high density and dense microstructure can be obtained after sintered at 1400 ℃ for 4 h. Compared with those prepared by the conventional ceramic route, 5 CLT-5 CMN ceramics produced by the reaction-sintering process exhibit slightly higher dielectric constant and Q×f value. Fine microwave dielectric properties of ε_r= 56.4, Q×f= 48,550 GHz and T_f = ＋8.7 ppm/℃ for 5 CLT-5 CMN ceramics sintered at 1400 ℃ for 4 h are obtained, suggesting reactionsintering process is a simple and efficient method to produce pure phase 5 CLT-5 CMN ceramics as a potential candidate for the fabrication of microwave devices.