Microwave Dielectric Properties of Low-Firing Li2MO3 (M=Ti, Zr, Sn) Ceramics with B2O3-CuO Addition

In this work, the sintering behaviors, microwave dielectric properties, and chemical compatibility with silver of pure and B2O3–CuO addition Li2MO3 (M=Ti, Zr, Sn) ceramics were studied. The 1 wt% B2O3–CuO addition does not affect the phase composition of Li2MO3 (M=Ti, Zr, Sn) and no secondary phase could be observed from XRD analysis. The sintering temperatures can be lowered from above 1200°C to around 900°C by 1 wt% B2O3–CuO addition. XRD analysis of cofired ceramics indicates that the Li2MO3 (M=Ti, Zr, Sn) ceramics are chemically compatible with silver. With 1 wt% B2O3–CuO addition, both Li2TiO3 and Li2SnO3 ceramics can be sintered well and possess good microwave dielectric properties with a permittivity of ∼19.67, a Q×f value of ∼46 300 GHz, a temperature coefficient of resonant frequency (TCF) of ∼+31.3 ppm/°C, and a permittivity of 13.73, a Q×f value of 36 400 GHz and a TCF about +27.4 ppm/°C, respectively.