Formation and microwave dielectric properties of the Mg₂V ₂O₇ Ceramics

The formation process and microwave dielectric properties of the Mg ₂V₂O₇ ceramics were investigated. The MgV ₂O₆ phase that was formed at around 450°C interacted with remnant MgO above 590°C to form a homogeneous monoclinic Mg ₂V₂O₇ phase. Finally, this monoclinic Mg ₂V₂O₇ phase was changed to a triclinic Mg ₂V₂O₇ phase for the specimen fired at 800°C. Sintering at 950°C for more than 5 h produced high-density triclinic Mg₂V₂O₇ ceramics. In particular, the Mg₂V₂O₇ ceramics sintered at 950°C for 10 h exhibited the good microwave dielectric properties of ε_r=10.5, Q × f=58 275 GHz, and τ_f=-26.9 ppm/°C.