By means of three-dimensional micromagnetic finite element modeling, the La
ndau structure of the magnetization is calculated as a minimum energy arran
gement 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 m
ajor domains in the prism is found to be given by an asymmetrical Bloch wal
l (Hubert-LaBonte wall). The result indicates an asymmetrical shape of the
closure domains at the surfaces. Adaptive mesh refinement strategies are em
ployed 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].