Complex impedance analysis on a layered perovskite-like ceramic: La ₃Ti ₂TaO ₁₁

Crystalline La ₃Ti ₂TaO ₁₁ ceramics using solid-state ceramic route was prepared and the electrical properties of La ₃Ti ₂TaO ₁₁ ceramics were investigated by ac-impedance analysis. La ₃Ti ₂TaO ₁₁ samples were prepared by high temperature solid-state reactions of high-purity raw powders of La ₂O ₃ and TiO ₂. Stoichiometric amounts of the raw powders were weighed and ball milled using zirconia balls for 4 h in plastic containers with ethanol as media. The powders were calcined at 1350° for 4 h. They were then remilled well and mixed with 5 wt.% solution of PVA as a binder. Dense ceramics with relative densities above 90% were obtained when sintered above 1510°C. Only a single, semicircular arc in the impedance complex plane was observed for a fixed temperature. With increasing sintering temperature, the grain size of the ceramics was slightly increased, while the porosity decreased.