Investigation on low-temperature sinterable behavior and tunable dielectric properties of BLMT glass-Li2ZnTi3O8 composite ceramics

The novel low-temperature sinterable ceramic composites were fabricated by mixing B2O3-La2O3-MgO-TiO2 (BLMT) glass with Li2ZnTi3O8 ceramic. All composites could be well sintered at 900 °C for 2 h through liquid-phase sintering and viscous sintering process. With BLMT glass increasing, the main phase of composites changed from Li2ZnTi3O8 to LaBO3 phase crystallized from glass. Nevertheless, the rutile phase was observed in composites with ≥10 wt% glass, which could adjust the temperature coefficient of resonant frequency (τf) to near-zero owing to the opposite τf value to other phases. Simultaneously relative permittivity (εr) and quality factor (Q×f) could be controlled by varying the content of Li2ZnTi3O8 ceramic and BLMT glass. The composite with 20 wt% glass exhibited excellent dielectric properties: εr = 22.7, Q × f = 19,900 GHz, and τf  = 0.28 ppm/°C. In addition, the good chemical compatibility between the composite with 5 wt% glass and Ag electrode made it as a potential candidate for LTCC technology.