A novel microwave dielectric ceramic Li2NiZrO4 with rock salt structure
Low loss Li2NiZrO4 ceramics with rock salt structure were successfully prepared by the solid-phase reaction method. The relationship between sintering temperature, phase composition and dielectric properties of Li2NiZrO4 ceramics was reported for the first time. The grain size gradually increased and the porosity decreased with the sintering temperature increasing. When the sintering temperature exceeds 1300 °C, the grains grow abnormally and some grains begin to melt. The XRD patterns indicated the second phase ZrO2 appeared due to the volatilization of lithium. The grains grow abnormally and a second phase of ZrO2 increased the loss of Li2NiZrO4 ceramics. The samples sintered at 1300 °C possessed the best dielectric properties: εr = 12.3, Qf = 20000 GHz, τf = −23.4 ppm °C−1, which would make the ceramic a possible candidate for millimeter-wave applications.