Stabilized temperature-dependent dielectric properties of Dy-doped BaTiO3 ceramics derived from sol-hydrothermally synthesized nanopowders

Monodisperse Dy-doped BaTiO3 nanopowders (xDBT) with x=0, 1, 2, 3, 4, 5 mol% has been synthesized via a modified sol-hydrothermal method. And the influence of Dy3+ on the crystal structure, micromorphology and dielectric properties of xDBT ceramics has been investigated. It’s found that Dy3+ slightly affects the shape of the xDBT nanopowders, whereas excess Dy3+ would cause the formation of the Dy(OH)3 impurity. In addition, the grain growth during a sintering process is suppressed with the Dy3+ incorporation. Further, the possible occupation of the Dy3+ has been extrapolated based on the variation of lattice volume and phase composition. A self-compensation mode involving the simultaneously occupation at Ba-site and Ti-site is observed in the samples with 4 mol% Dy. Importantly, stabilized temperature-dependent dielectric properties has been achieved at x=4 mol%, resulting from the diffuse phase transition behaviors (the calculated diffuse factor γ=1.952) induced by chemical inhomogeneity.