LI Xie ¹, WANG Hui ², WANG Tingting ¹, ZHU Xiaodong ³
(1. Department of Material and Chemical Engineering, Ningbo University of Technology, Ningbo 315000, Zhejiang, China; 2. Shanghai Advanced Research Institute, Shanghai 201210, China; 3. Ningbo Academy of Product Quality Supervision & Inspection, Ningbo 315000, Zhejiang, China)

Abstract: In this paper special formulas were designed for Eu₂O₃-doped (Ba_0.7Sr_0.3) TiO₃ electronic ceramics. Then samples were prepared by solid-state reaction sintering method. XRD and SEM were used to analyze their phase composition and microstructure. The piezoelectric impedance analyzer was used to analyze their dielectric constant and dielectric loss. The results showed that when Eu₂O₃ was doped, the dielectric constant of the ceramics was reduced at room temperature. However, the dielectric loss (tanδ) decreased first and then increased. When the Eu content was 0.03%, the tanδ was the lowest. The microstructure analysis found that with Eu doping, the BST ceramics were still composed of the perovskite phase and tungsten bronze phase, but the grains of the samples changed. When the doping was 0.05%, their crystal development was the best. Therefore, Eu doping could obviously change the ceramic microstructure and dielectric properties.

Key words: BST ceramics; perovskite phase; rare earth-doped; dielectric constant; solid solution