Abstract
BaCu(B2O5) (BCB) additive was used to decrease the sintering temperature of the BaTi4O9 ceramics. The amount of Ba4Ti13O30 second phase increased with the addition of BCB, whereas that of the BaTi4O9 phase decreased. The bulk density and dielectric constant (εr) considerably increased with the addition of BCB. An increase in the Q-value was also observed for the BaTi4O9 ceramics with a small amount of BCB. Good microwave dielectric properties with values of εr=32, Q ×f=10800 GHz and τf=32 ppm/°C were obtained in the BaTi4O9 ceramics with 12.0 mol % of BCB sintered at 875 °C for 2 h.