Dielectric properties of B2O3-doped BiNbO4 ceramics

The densified B2O3-doped BiNbO4 ceramics were obtained after sintering at 960 degreesC. The dielectric properties of B2O3-doped BiNbO4 ceramics were studied. Samples sintered in air show low frequencies (from 1 to 100 kHz) dielectric relaxation behaviors at about 150 degreesC. The dielectric relaxation temperature would decrease when the sample was sintered in N-2. The dielectric constant and loss at low frequencies increased rapidly and the microwave dielectric properties deteriorated with increasing B2O3 content when sintered in N-2. The dielectric constant, Q-value and TCF-value of the 0.4 wt.% B2O3-doped BiNbO4 ceramic at 4.8 GHz are 41.5, 4400 and -2.4ppm/degreesC, respectively. A defect model was proposed for the explanation of dielectric behavior of B2O3-doped BiNbO4 ceramics. (C) 2004 Elsevier Ltd and Techna Group S.r.l. All rights reserved.