On the conductivity of magnetite below the Verwey transition

Abstract

Using existing data, the authors emphasise that in the range Tv>T> approximately Tv/2 the electrical conductivity sigma of Fe3O4, and some other mixed-valence oxides, is described better by sigma varies as exp(T) than by an Arrhenius law. A possible explanation of this dependence is offered, based on incoherent tunnelling of electrons between neighbouring sites.