Thick ferromagnetic films and their anisotropies as described by second   order perturbed Heisenberg Hamiltonian
  Second and fourth order anisotropy dependence of energy of thick simple cubic ferromagnetic films with 10000 layers is explained using Heisenberg Hamiltonian with second order perturbation in this manuscript. The second and fourth order anisotropy constants were assumed to be constants through out the film. When the fourth order anisotropy is given by fourth order anisotropy of 6, the sc(001) ferromagnetic thick films with 10000 layers can be easily oriented in 0.6 radians direction for the energy parameters given this report. Under the influence of the second order anisotropy given by second order anisotropy of 6.3, the easy direction of sc(001) film with 10000 layers is given by 0.66 radians. Although the energy varies periodically in all cases, the maximum energy considerably decreases with fourth order anisotropy constant. According to 3-D plots, energy under influence of second order anisotropy is larger than energy under influence of fourth order anisotropy. 
P. Samarasekara
cond-mat.mtrl-sci