Electrical properties and cation migration in manganese ferrites I. Temperature dependences

High temperature behaviour of the electrical conductivity and the Seebeck effect in MnFe₂O₄ single crystals is studied both experimentally and theoretically. Various heat cycles in the temperature range 300–600 °C lead to marked changes in the temperature dependences of electrical properties. A two donor level model of electrical conduction is used to explain the observed behaviour. The influence of the cation migration between the tetrahedral and the octahedral sites of the spinel lattice on electrical properties of Mn ferrites is demonstrated.