Electrical Properties and Cation Migration in MgMn₂O₄

Abstract

Abstract The influence of the cation migration process on the electrical properties of MgMn 2 O 4 is investigated. By measuring the temperature dependence of the electrical resistance and thermoelectric power, it is possible to study the migration process of the cations in the spinel lattice, and to establish the temperature range in which the tetragonal‐cubic phasechange occurs. By using the thermoelectric power data it is possible to specify the valence formulae of samples which have been quenched or slow‐cooled from high temperature. The electrical conduction occurs by a hopping mechanism between the octahedral‐site Mn 3+ and Mn 4+ ions, and involves very low mobilities.