Defect structure and dielectric behavior in SrTi1-x(Zn1/3Nb2/3)xO3 ceramics

Abstract SrTi 1-x (Zn 1/3 Nb 2/3 ) x O 3 ceramics with various defect concentration were designed and prepared via solid state reaction method, the close relationships between defect structure and dielectric behavior of were investigated in detail. High permittivity (∼9100) and low dielectric loss (∼0.03) are achieved at an optimum doping concentration (x = 0.015) due to the enhanced local polarization, while the dielectric properties deteriorate because of the increasing self-compensation as the impurity concentration continuously increases. Further investigation shows that, the giant permittivity is owing to the defect polarization, including off-center Zn 2+ /Ti 3+ , combination center ( N b T i · − e ′ ∙ T i 4 + ) and defect dipoles ( T i 3 + − V O · · − T i 3 + ) as well as the contribution from interface polarization, low dielectric loss results from the localization of electron by the defect dipoles/clusters. These findings provide the requisite data and idea for defect design in complex perovskite materials.