Preparation and electrical properties of new oxide ion conductors Ce 6− xDy xMoO 15− δ (0.0 ≤ x ≤ 1.8)

Abstract

Ce 6− x Dy x MoO 15− δ (0.0 ≤ x ≤ 1.8) were synthesized by modified sol–gel method. Structural and electrical properties were investigated by means of X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The XRD patterns showed that the materials were single phase with a cubic fluorite structure. Impedance spectroscopy measurement in the temperature range between 350 °C and 800 °C indicated a sharp increase in conductivity for the system containing small amount of Dy 2O 3. The Ce 5.6Dy 0.4MoO 15− δ detected to be the best conducting phase with the highest conductivity ( σ t = 8.93 × 10 −3 S cm −1) is higher than that of Ce 5.6Sm 0.4MoO 15− δ ( σ t = 2.93 × 10 −3 S cm −1) at 800 °C, and the corresponding activation energy of Ce 5.6Dy 0.4MoO 15− δ (0.994 eV) is lower than that of Ce 5.6Sm 0.4MoO 15− δ (1.002 eV).