Dielectric properties and substitution preference of yttrium doped barium zirconium titanate ceramics

The dielectric properties of Ba(Zr_0.25Ti_0.75)O₃+xY ₂O₃ ceramics are investigated. We believe that, integrating with the lattice parameters, there is an alternation of substitution preference of yttrium ions for the host cations in perovskite lattice that is responsible for the Curie point. The T_c rises with the increase of Y ³⁺ doping when the doping content is less than 0.05 at%, owing to the replacement of Y ³⁺ ions for Ba²⁺ ions at the A-site; when the Y ³⁺ content is more than 0.05 at%, Y ³⁺ ions tend to occupy the B-site in perovskite lattice, causing a drop of T_c. Owing to the modifications of Y ³⁺ doping, the loss tangent of BZT ceramics is depressed remarkably, making it a superior candidate to replace widely used lead-contained ceramics.