Micromagnetics of anisotropic cylinders

We extend the micromagnetic description of magnetization reversal in long cylindrical particles to materials with magnetocrystalline anisotropy with the preferred axis coincident with the particle axis. The magnetocrystalline and shape anisotropy energies depend differently on the orientation of the magnetization. Because of this, neither magnetization curling (which is an exact solution for isotropic cylinders) nor magnetization buckling satisfy the nucleation equations exactly. However, magnetization curling and buckling may be used as overconstrained approximations to construct nucleation or switching curves for all orientations of the cylinder in an external field. Stability of nucleation is examined by calculating the free energy of magnetization to fourth order in the amplitude of the nucleation mode. The results of this calculation are useful in the construction of complete magnetization cycles.