Low temperature sintering and microwave dielectric properties of Li2ZnTi3O8-TiO2 ceramics doped with BaO-B2O3-ZnO glass

A low temperature co-fired ceramic (LTCC) material of Li2ZnTi3O8-TiO2 (L(2)ZT(3)-TiO2) doped with BaO-B2O3-ZnO (BBZ) glass were prepared by conventional solid-state method. The effects of BBZ glass on the phase composition, microstructure, and microwave dielectric properties were investigated. The results indicated that BBZ glass as a sintering aid could effectively reduce the sintering temperature of L(2)ZT(3)-TiO2 ceramic below 950 A degrees C. The XRD patterns indicated that L(2)ZT(3)-TiO2 ceramic consisted of Li2ZnTi3O8 and TiO2 phases. BBZ glass addition did not change the phase composition. In addition, the SEM demonstrated that BBZ glass could significantly improve the grain growth and densification. The sintering mechanism was analyzed through the wetting behavior and the activation energy (Ea). When added 2.5 wt% BBZ glass, the average activation energy reduced from 492.38 +/- 139.03 to 370.69 +/- 20.98 kJ/mol, which indicated that the BBZ glass not only effective lowered the sintering temperature but also promoted the sintering process. The L(2)ZT(3)-TiO2 ceramic with 2.5 wt% BBZ sintered at 925 A degrees C for 4 h had excellent microwave dielectric properties of epsilon(r) = 26.3, Q x f = 36,554 GHz and tau(f) = - 4.16 ppm/A degrees C. In addition, the good chemical compatibility of this material with Ag electrode could make it as a potential candidate for LTCC technology.