Structure and Microwave Dielectric Property of BaAl2Si2O8 with Li2O-B2O3-SiO2 Glass Addition

The BaAl2Si2O8-xwt%Li2O-B2O3-SiO2 (x=0, 0.1, 0.3, 0.5, 1.0, 2.0) ceramics with small amount of Li2O-B2O3-SiO2 (LBS) glass addition were prepared by solid state sintering. The sintering temperature, structure and microwave dielectric properties of BaAl2Si2O8 (BAS) ceramics with xwt%LBS glass addition were investigated. The results show that the LBS glass can greatly reduce the sintering temperature, promote the growth of grain and the transformation of hexacelsian-to-celsian of BAS ceramics. As x=0.1, all the hexacelsian were transformed into celsian, and the second phase was not observed as x <= 2.0. The 0.3wt%LBS glass can promote the density, dielectric constant and Q x f value increase, and the absolute value of tau(f) decrease. Especially, the BAS ceramics with the 0.3wt%LBS glass addition sintered at 1275 degrees C shows a good Q x f of 34570 GHz, and the dielectric properties are epsilon(r) = 6.74 and tau(f) = -15.97 x 10(-6)/v.