INVERSE SPINEL COBALT FERRITE ULTRA-THIN FILMS AS EXPLAINED BY SECOND ORDER PERTURBED HEISENBERG HAMILTONIAN

摘要

The second order perturbed Heisenberg Hamiltonian has been employed to investigate the magnetic properties of ultra-thin cobalt ferrite films with three unit cells. The variation of classical magnetic energy with second order magnetic anisotropy, spin exchange interaction and angle has been plotted in order to observe the easy and hard directions of cobalt ferrite ultra-thin films. According to our 3-D and 2-D plots, the ultra-thin cobalt ferrite film can be easily aligned along some particular directions at some certain values of second order magnetic anisotropy and spin exchange interaction. In addition, the energy maximums can be also observed at some certain values of second order magnetic anisotropy and spin exchange interaction indicating that it is difficult to align the film at these values of energy parameters. However, the easy and hard directions described at this manuscript are valid only for the special values of the energy parameters used for this simulation.