Effect of adding Ti2Nb10O29 on the dielectric properties of MgNb2O6 microwave dielectric ceramics

MgNb2O6- x wt% Ti2Nb10O29 (x = 0, 2, 4, 6, 8, 10) microwave dielectric ceramics with near zero temperature coefficient of resonance frequency τf were prepared by the solid-state reaction technique. The effects of Ti2Nb10O29 incorporation on the microstructure and dielectric properties of MgNb2O6 were investigated to probe the formation and sintering behavior of each phase. The results show that the appropriate Ti2Nb10O29 addition can promote the sintering of MgNb2O6 and improve the density of the ceramics. The quality factor Q × f was decreased with the increasing of Ti2Nb10O29, but, at the same time, the dielectric constant εr and the temperature coefficient of resonance frequency τf were improved, which is consistent with the theoretical calculation. When the addition amount x is equal to 4, the ceramic sample has the best microwave dielectric properties after sintering at 1280 °C for 4 h: εr = 21.72, Q × f = 76,850 GHz, τf = -9.6 × 10–6/°C.