Nature of ionic conductivity of lanthanide tungstates with imperfect scheelite structure

Abstract

Electric properties of tungstates with imperfect scheelite structure, Ln₂(WO₄)₃ (Ln = La, Sm, Eu), are studied; the charge carrier type is determined in these phases. It is found that the conductivity type of Ln₂(WO₄)₃ is predominantly ionic, though there is a contribution of n-type electron conductivity component in the case of Eu₂(WO₄)₃. The Tubandt method was used to establish a negligible contribution of the [WO₄]^2– anion into transport, which, together with the results of the EMF technique, points to the predominantly oxygen character of conductivity.