MAGNETIZATION PROCESSES AND MECHANISM FOR KINETIC ANOMALIES IN MAGNETIC NANOSTRUCTURES

Spin-reorientation phase transitions in anisotropic antiferromagnetic superlattices of the Co/Pt type are examined theoretically. Expressions are derived for the critical lines of second-order phase transitions to the ferromagnetic phase from the angular phase. Stability conditions are derived. They involve the external field, the anisotropic constant, the exchange energy, and the number of layers in the superlattice. A mechanism is proposed for explaining kinetic anomalies in superlattices. It incorporates a scattering of conduction electrons by ''magnetic'' energy barriers which exist if the magnetizations of neighboring magnetic layers are antiparallel. Expressions are derived for the mean free path and the magnetoresistance as a function of the magnitude of the external magnetic field. Numerical estimates are found.