Anomalies of the magnetoresistance of ferrites
Lomonosov Moscow State University, Department of Physics, Leninskie Gory 1 build. 2, Moscow, 119991, Russian Federation
The results of measurements of the field and temperature dependences of the magnetoresistance of manganese ferrite and several other spinel ferrites are presented in a systematic manner and analysed. In magnetic fields in excess of the technical saturation and at temperatures below the Curie point these ferrites have two physically different components of the isotropic negative magnetoresistance. One of them is due to the scattering of conduction (’hopping’) electrons on paraprocess-induced variations of the order of the magnetic cations. The second component is interpreted on the basis of a ’magnetoelectron sublattice’ model proposed by the author. Manifestations of the magnetoresistance in the vicinity of various phase transitions in spinel ferrites are considered.