Investigation into the high permittivity [(K_0.5Bi_0.5)_xBi_1−x](W_xV_1−x)O₄ (0 ≤ x ≤ 0.1) ceramic sintered at low temperature

Abstract

The high-k [(K_0.5Bi_0.5)_xBi_1−x](W_xV_1−x)O₄ (0 ≤ x ≤ 0.1) ceramic was prepared via the modified solid-state reaction method. When x = 0.1, the monoclinic scheelite structure was obtained at low sintering temperature. However, when x = 0.2, the impurity phase was found. After being sintered at 650 °C for 6 h, the [(K_0.5Bi_0.5)_0.1Bi_0.9](W_0.1V_0.9)O₄ ceramic possesses the best properties with a relative permittivity of 78.7, Q × f value of 7210 GHz and a temperature coefficient of +163 ppm/°C at the frequency of 4.11 GHz. Compared with the result of the pure BiVO₄ ceramic, the sintering temperature dropped from 740 to 650 °C and the relative permittivity was increased from 67.8 to 78.7. Due to the high relative permittivity and the low sintering temperature, the [(K_0.5Bi_0.5)_0.1Bi_0.9](W_0.1V_0.9)O₄ ceramic is potential to realize the miniaturization in communication application.