Structure, composition, microwave dielectric properties and improved ultra-low temperature sintering characteristics of Lyonsite structural Li₂Mg₂Mo₃O₁₂ ceramic

(1-x)Li2Mg2Mo3O12-xTiO(2) (x = 0.1-0.5) composite ceramics are prepared by solid-state sintering process. And the structure, composition, microwave dielectric properties and ultra-low temperature sintering characteristics are studied. The result of two-phase (Li2Mg2Mo3O12 and TiO2) coexistence is definitely identified through XRD, mapping and Raman analysis along different regions. Furthermore, as the sintering temperature increases, the enhanced degree of densification plays a positive role in determining microwave dielectric properties. Sintering additives are used to lower sintering temperature of 0.6Li(2)Mg(2)Mo(3)O(12)-0.4TiO(2) composite ceramics, where 1 wt % H3BO3 is applied to reduce the temperature from 750 degrees C to 700 degrees C and maintain excellent microwave dielectric characteristics. The cooling mechanism of sintering aids are also thoroughly studied. In all, 0.6Li(2)Mg(2)Mo(3)O(12)-0.4TiO(2) composite ceramic with 1 wt% H3BO3 sintered at 700 degrees C displays excellent microwave dielectric properties (epsilon(r)similar to 11.27, Q x f similar to 43056 GHz, tau(f) similar to -3 ppm/degrees C). It can be served as a pioneering candidate in applications of ULTCC (ultra-low temperature co-fired ceramic).