LAUSR

Abstract The Q × ƒ values of SmNbO4 ceramics had been effectively optimized by MgO doping, and a series of high-Q SmNbO4-x MgO (0.5 ≤ x ≤ 4.0) ceramics had been successfully prepared with conventional solid reaction process. The phase composition, microstructure and microwave dielectric properties had been investigated with different content of MgO addition. Two phases, surrounded by each other which indexed as SmNbO4 and MgO, had been detected in SmNbO4-x MgO ceramics. It was found that the grain growth of SmNbO4-x MgO ceramics could be well promoted by MgO additive, owing to the similar c/a values between the two crystal structures. Based on the structural characteristic of SmNbO4-x MgO ceramics, the variation in dielectric constant of SmNbO4-x MgO ceramics was verified to satisfy with the Lichtenecker logarithmic mixing rule. Importantly, the Q × ƒ values of SmNbO4-x MgO ceramics increased as a function of MgO content, which was analyzed to result from the improved microstructure.