Effects of Mg2.05SiO4.05 addition on phase structure and microwave properties of MgTiO3–CaTiO3 ceramic system

• The (1−x) MgTiO3–xMg2.05SiO4.05–0.06CaTiO3 composite ceramics were prepared.
• The results indicated that exceeding Mg in Mg2.05SiO4.05 not only hold back the formation of MgSiO3 but also inhibits the formation of second phase MgTi2O5.
• A new microwave dielectric material has optimal dielectric properties.

The (1−x) MgTiO3−xMg2.05SiO4.05–0.06CaTiO3 ceramic system composite dielectric ceramics with different amounts of Mg2.05SiO4.05 addition were prepared by solid state reaction method. The results indicated that exceeding Mg in Mg2.05SiO4.05 not only hold back the formation of MgSiO3 but also inhibits the formation of second phase MgTi2O5. A new microwave dielectric material, 0.8MgTiO3–0.2Mg2.05SiO4.05–0.06CaTiO3 ceramics sintered at 1380 °C for 4 h had optimal dielectric properties (εr=15.4, Q×f=72,705 GHz and τf=−1.45 ppm/°C) which satisfied microwave applications in resonators, filters and antenna substrates.