LOW-TEMPERATURE SINTERING AND MICROWAVE DIELECTRIC PROPERTIES OF (Zn0.65Mg0.35)TiO3-CaTiO3 CERAMICS WITH H3BO3 ADDITION
نویسندگان
چکیده
Low-melting H3BO3, acting as sintering aid, was used to reduce the sintering temperature of 5 wt.% CaTiO3-doped (Zn0.65Mg0.35)TiO3 ceramics. The sintering behaviors, microstructures and microwave dielectric properties with different amounts of H3BO3 addition were investigated. The results showed that H3BO3 additive was very effective for lowering the sintering temperature and improving the bulk density during sintering. This was due to the promotion of liquid-phase sintering. In the case of 0.25 wt.% H3BO3 addition, fine-grained structure was observed, whereas abnormal grain growth was occurred when 3 wt.% H3BO3 was doped. It was found that the addition of H3BO3 improved the dielectric constant (εr) and quality factor (Q × f) .When 5 wt.% CaTiO3 and 3 wt.% H3BO3 were added, the (Zn0.65Mg0.35)TiO3 ceramics could be sintered at 950~1000°C and showed excellent microwave dielectric properties: ε ≈ 20, Q × f > 48000 GHz (at 8 GHz) and τf ≈ 5 ppm/°C.
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