Microstructure and dielectric properties of (K_0.5Na_0.5)NbO₃–Bi(Zn_2/3Nb_1/3)O₃ − xmol%CeO₂ lead-free ceramics for high temperature capacitor applications

(K_0.5Na_0.5)NbO₃–Bi(Zn_2/3Nb_1/3)O₃ − xmol%CeO₂ [0.97KNN–0.03BZN − xCeO₂] lead-free ceramics were synthesized and the phase structure, microstructure and dielectric properties were investigated. Dielectric studies reveal that the 0.97KNN–0.03BZN − 1.0CeO₂ ceramics show excellent dielectric properties at a broad usage temperature range (150–350 °C): the dielectric permittivity is near 1900 (at 10 kHz) with the capacitance variation (ΔC/C_150 °C) no more than ±10 %; the temperature coefficient of permittivity (TC_ε) is as low as −162 ppm/°C; the corresponding dielectric loss is less than 2.5 %. These results indicate that the 0.97KNN–0.03BZN − 1.0CeO₂ ceramics are promising candidates for high temperature multilayer ceramic capacitor applications.