The low-temperature sintering and microwave dielectric properties of (Zn0.7Mg0.3)TiO3 ceramics with H3BO3

The effects of the addition of H3BO3 on the microstructure, phase formation, and microwave dielectric properties of (Zn0.7Mg0.3)TiO3 ceramics sintered at temperatures ranging from 890 °C to 950 °C are investigated. H3BO3 as a sintering agent can effectively lower the sintering temperature of ZMT ceramics below 950 °C due to the liquid-phase effect. The microwave dielectric properties are found to strongly correlate with the amount of H3BO3. With the increase in H3BO3 content, the dielectric constant (er) monotonically increases, but the quality factor (Q × f) reaches a maximum at 1 wt% H3BO3, and the apparent density of ZMT ceramics with H3BO3 ≥ 1 wt% gradually decreases. At 950 °C, the ZMT ceramics with 1% H3BO3 exhibit excellent microwave dielectric properties: er = 19.8, and Q × f = 43800 GHz (8.94 GHz).