Cobal Ferrite Films as Described by Third Order Perturbed Heisenberg Hamiltonian

Abstract

Magnetic properties of thick films of Cobalt ferrite have been investigated using third order perturbed modified Heisenberg Hamiltonian at different values of second and fourth order magnetic anisotropy. Thick films with up to 10,000 layers have been employed for this investigation. The magnetic energy versus number of layers, second and fourth order anisotropy have been plotted in order to find the magnetically easy and hard directions of cobalt ferrite films. Energy has minimum and maximum values at certain values of second and fourth order anisotropy values, indicating that that there are magnetically easy and hard directions. Energy shows the same type of variations with number of layers in the film. For the values considered in this manuscript, the easy direction of magnetization was found to be 1530 with the normal line drawn to the film surface. However, the easy axis direction depends on the values of parameters used in simulation. Determination of easy directions of magnetic films is important in applications of magnetic memory devices.