Synthesis and microwave dielectric properties of new high quality Mg 2 NdNbO 6 ceramics

New high‐quality microwave dielectric ceramics Mg 2 NdNbO 6 were prepared by conventional solid‐state sintering method. The phases, micro‐structures and microwave dielectric properties of Mg 2 NdNbO 6 ceramics were investigated at sintering temperature in the range of 1275°C‐1400°C. The X‐ray diffraction patterns showed that the peaks of the compounds were attributed to two phases, including the main crystalline phase of NdNbO 4 that was indexed as the monoclinic phase and MgO as the second phase. Well‐developed microstructures of Mg 2 NdNbO 6 ceramics can be achieved, and the grain size reached the maximum value (1.63 μm) at 1375°C. As the sintering temperature increased, the dielectric constant, temperature coefficient of resonant frequency and apparent density remained almost unchanged, however, the significant change in the quality factor was observed. At 1375°C, Mg 2 NdNbO 6 ceramics possessed excellent microwave dielectric properties: ε r = 16.22, Q × f = 116 000 GHz and τ f = −30.96 ppm/°C.