Electronic magnetic relaxation in manganese ferrites

Two electronic magnetic relaxation phenomena are reported for the manganese ferrite system, which are both explained by electron hopping processes between octahedral iron ions: the first one by hopping between Fe²⁺ and Fe³⁺ ions with a Mn²⁺-ion as nearest neighbor and the second one by hopping between iron ions with only iron nearest neighbors. Electrical conductivity measurements performed on a single crystal, showed further that the composition dependence of activation energy for the conductivity behaves in a similar way as the magnetic activation energy which is a strong evidence for the proposed Fe²⁺-Fe³⁺ electron exchange mechanism.