Effect of Fe-doping on the dielectric properties of BaTi0.8Sn0.2O3 ceramics

In this study, BaTi0.8Sn0.2O3 ceramics doped by Fe powders were prepared by the traditional solid-state sintering method. The crystal phases, microstructures, and dielectric properties of the samples were studied. The doping of Fe powders contributed to refining the crystal grain size, promoting the densification of microstructure, and enhancing the dielectric properties. The XPS and XRD analysis revealed that the Fe replaced the B-site (Ti or Sn) of the BaTi0.8Sn0.2O3 resulting in the coexist of Fe2+ and Fe3+ due to the insufficient oxygen, which introduced defect dipoles and nano-polar regions and further influenced the permittivity, the Tc (Curie temperature) and the dielectric tunability. When the content of Fe additives was 1 wt%, the BaTi0.8Sn0.2O3 ceramics had dense microstructure and the lowest permittivity of 924, the Tc of −49.0 °C and high dielectric tunability of 64%. These promising properties make Fe doped BaTi0.8Sn0.2O3 ceramics more suitable for the application of dielectric tunable components.