Dielectric properties of B2O3-doped BiNbO4 ceramics

Abstract The densified B 2 O 3 -doped BiNbO 4 ceramics were obtained after sintering at 960 °C. The dielectric properties of B 2 O 3 -doped BiNbO 4 ceramics were studied. Samples sintered in air show low frequencies (from 1 to 100 kHz) dielectric relaxation behaviors at about 150 °C. 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 B 2 O 3 content when sintered in N 2 . The dielectric constant, Q -value and TCF-value of the 0.4 wt.% B 2 O 3 -doped BiNbO 4 ceramic at 4.8 GHz are 41.5, 4400 and −2.4 ppm/°C, respectively. A defect model was proposed for the explanation of dielectric behavior of B 2 O 3 -doped BiNbO 4 ceramics.