The recent identification of interstitial oxide ion conductivity in the La2NiO4+δ type oxides had indicated a new direction in the search for new oxide ion conductors. Whilst materials containing significant levels of interstitial oxide ions were relatively uncommon, it was apparent that there were a number of materials with substantial interstitial concentrations yet to be investigated in terms of their oxide ion mobility. An initial study of CeTaO4+δ (δ = 0.06 to 0.17) was made in an effort to expand the number of types of material known for their possible oxide ion conductivity. Materials were produced and investigated by alternating-current impedance spectroscopy and a significant conductivity recorded. Further work on this preliminary data was required in order to determine the nature of this conductivity.

CeTaO4+δ (0.06 < δ < 0.17) as an Interstitial Oxide Ion Conductor. S.J.Skinner: Solid State Ionics, 2002, 154-155, 325-9