Computation of the magnetic domain structure in bulk permalloy

By means of three-dimensional micromagnetic finite element modeling, the Landau structure of the magnetization is calculated as a minimum energy arrangement in a rectangular permalloy block (1 mu m x 500 nm x 250 nm). On the surface, so-called Neel caps are observed. The transition between the two major domains in the prism is found to be given by an asymmetrical Bloch wall (Hubert-LaBonte wall). The result indicates an asymmetrical shape of the closure domains at the surfaces. Adaptive mesh refinement strategies are employed to raise the accuracy of the calculation. It is shown that the mesh refinement is capable to reduce discretization errors significantly. [S0163-1829(99)07733-4].