基于(Sr,Ca)ZrO3-Sr0.75Bi0.167TiO3陶瓷的U2J介质材料的制备与介电性能

Paraelectric U2J dielectrics have great potential for use in power electronics. In this work, fabrication and dielectric properties of U2J dielectrics based on (1-x)Sr 0.75 Bi 0.167 TiO 3 -x(Sr y Ca 1-y )ZrO 3 ceramics system were investigated. The impurity phase exists in (1-x)Sr 0.75 Bi 0.167 TiO 3 -xCaZrO 3 for x = 0.2–0.5. The content of impurity phase decreases in 0.5Sr 0.75 Bi 0.167 TiO 3 -0.5(Sr y Ca 1-y )ZrO 3 with increasing Sr content. The optimized dielectric properties are obtained at x = 0.5 and y = 0.2, and the ceramics satisfies U2J dielectric requirements (τ ε = − 683 ppm °C −1 ) together with high dielectric constant (124.5) and low dielectric loss (< 0.001). The modified temperature coefficient for the present samples is due to the rattling effect of A-site ion for the smaller A-site bond valence. With the addition of Li 2 CO 3 and MnCO 3 , the sintering temperature for dense ceramic is reduced from 1350 to 1240 °C and nonreducible characteristics are obtained when sintering in N 2 atmosphere. The present ceramic has potential application for Cu electrode U2J dielectric if the sintering temperature can be lowered further.