The Ba11W4O23 (or Ba1.75(BaW)O5.75) had a derivative perovskite (ABO3) structure with vacancies ordered in the A sub-lattice, but disordered in the O sub-lattice, suggesting the potentiality as an oxide ion electrolyte. Electrical conductivities of Ba11W4−xTaxO23−0.5x were characterized as functions of temperature, O activity, water vapour activity, and composition x (0.1, 0.5, 1.0, 2.0). It was found that the compound was indeed an oxide ion conductor, over a wide O activity range, with a moderate ionic conductivity, compared with the conventional electrolyte oxides. The conductivity was little dependent on x, but for x = 1 where an appreciable depression of the conductivity occurred. The oxide also exhibits a proton conductivity at temperature below 800C.

A New Potential Electrolyte Ba11W4O23 - Novel Structure and Electrical Conductivity. J.S.Ha, E.Lee, S.T.Hong, H.I.Yoo: Solid State Ionics, 2008, 179[21-26], 1066-70