Fabrication of X8R-type Ba0.991Bi0.006TiO3@Nb2O5–Co3O4–La2O3@ZnO–B2O3–SiO2 ceramics with a fine-grained microstructure and low sintering temperature

Abstract

BaTiO3-based ceramics with a fine-crystalline microstructure, high temperature stability, and low sintering temperature have potential applications in multilayer capacitors (MLCCs). Here, a novel core–shell structured Ba0.991Bi0.006TiO3@Nb2O5–Co3O4–La2O3@ZnO–B2O3–SiO2 (BBT@NCL@ZBSO) ceramics were prepared by a double-coating method. The NCL was to improve the temperature stability of the ceramics and produce fine-grained ceramics. The ZBSO coating layer was advantageous to reducing the sintering temperature. As a result, the sintering temperature of the samples decreased from more than 1300 to 1100 °C. Moreover the ceramics loaded with 4.0 wt% ZBSO coating content by low temperature sintering at 1100 °C show the optimum dielectric constant of 2841, the dielectric loss is 0.0044, and the average grain size of the ceramic is 300 nm, which is similar to the BBT@NCL powder particle size (285 nm). The results indicated that the low-temperature-sintered BBT@NCL@ZBSO ceramics could be a promising dielectric material for X8R-type MLCCs.