Influence of MgO-Al2O3-SiO2 additive on sintering behavior and microwave dielectric properties of Ba(Mg1/3Nb2/3)O3-MgO ceramics

In this work, MgO-Al2O3-SiO2 (MAS) glass ceramics were used as the liquid sintering aid to promote the sintering process of Ba(Mg1/3Nb2/3)O3-MgO ceramics. The influences of the MAS additions and the cooling rate on the sintering behavior, phase compositions, microstructure, and dielectric properties of the obtained ceramics were studied. The results showed that the addition of MAS significantly improved the sintering process of BMNMgO ceramics. The sintering temperature of the MAS-added BMN-MgO samples was reduced from 1470 degrees C to 1300 degrees C, and the holding time was reduced from 10 h to 30 min. The BMN-MgO ceramics with 5 wt% MAS glass ceramics sintered at 1300 degrees C for 30 min with a cooling rate of 1 degrees C/min obtained excellent dielectric properties at 7.5 GHz: epsilon r = 20.61, Q x f = 63,468 GHz, and tau f = - 1.72 ppm/degrees C.