Low-temperature sintering and microwave dielectric properties of Ba2Ti3Nb4O18 ceramics

Abstract

The effects of CuO and H3BO3 additions on the low-temperature sintering, microstructure, and microwave dielectric properties of Ba2Ti3Nb4O18 ceramics were investigated. The addition of less amount of CuO (< 1 wt%) considerably facilitated the densification of Ba2Ti3Nb4O18 ceramics. Appropriate addition of H3BO3 (< 3.5 wt%) remarkably improved the microwave dielectric properties of ceramics. The addition of H3BO3 and CuO successfully reduced the sintering temperature of Ba2Ti3Nb4O18 ceramics from 1300 to 1050 °C. Ba2Ti3Nb4O18 ceramics sintered at 1 050 °C for 4 h with the addition of 1.0 wt% CuO and 3.5 wt% H3BO3 exhibited good microwave dielectric properties: ɛ r = 33.74, Q·f = 13 812 GHz, and τ f = −5.35 ppm/°C at about 5.0 GHz.