Stress induced anisotropy and applied field dependence of second order perturbed energy of thick ferromagnetic films

The energy of thick ferromagnetic films up to 10000 layers has been explained in this report using classical Heisenberg Hamiltonian with second order perturbation. Especially the effect of applied magnetic field and stress on energy of sc(001) ferromagnetic thick films has been investigated. Under the influence of perpendicular magnetic field given by =  6, the sc(001) ferromagnetic film with 10000 layers can be easily oriented in 0.5 radians direction. The easy direction of sc(001) ferromagnetic film with 10000   layers was found to be 0.6  radians when the in-plane magnetic field of   = 4.2 is applied. Because the easy axis oriented magnetic films are useful in magnetic memory devices and monolithic microwave integrated circuits (MMIC), the determination of easy direction is important.  If the stress given by = 2.6 is applied in perpendicular direction to the film plane, the film can be easily oriented in direction of 3 radians. Energy under influence of perpendicular magnetic field is larger than the energy under the influence of in-plane magnetic field. After introducing the second order perturbation to the Heisenberg Hamiltonian, even some small variations of energy could be investigated as indicated in the graphs in this manuscript.

Keywords:  Ferromagnetic materials, thick films, Heisenberg Hamiltonian, stress induced anisotropy

DOI: http://dx.doi.org/10.4038/josuk.v6i0.4223

J Sci.Univ.Kelaniya 6 (2011) : 77-84