Microstructure and electrical properties of Mn/Y codoped Ba0.67Sr0.33TiO3 ceramics

Pure and Mn/Y codoped Ba0.67Sr0.33TiO3 (BST) ceramics were fabricated via the citrate-nitrate combustion technique, and the microstructure and electrical properties of BST ceramics were mainly investigated. The Mn/Y codoping concentration has a strong influence on the microstructure and electrical properties of BST ceramics. All BST ceramics possess a pure polycrystalline structure. The density, dielectric loss, leakage current, and ferroelectric properties are improved by codoping 0.5 mol% Mn and 1.0 mol% Y to BST. The relative density of 0.5 mol% Mn/1.0 mol% Y-codoped BST (BST0510) ceramics reaches 97.5% of the theoretical value. BST0510 ceramics have the lowest dielectric loss (tanδ < 0.0073 at 1 kHz) among all BST ceramics. BST0510 ceramics also demonstrate a low leakage current density (1.23 × 10−7 A/cm2) at an applied field of 10 kV/cm, and excellent ferroelectric properties with a remanent polarization of 2Pr = 15.327 μC/cm2 and a coercive field of 2Ec = 3.456 kV/cm. Therefore, the Mn and Y with optimum content help improve the electrical properties of BST materials.