Magnetic Ground State of a Thin-Film Element

By means of three-dimensional numerical calculations we studied possible micromagnetic configurations in a rectangular Permalloy-like thin-film element. The parameters were chosen to be compatible with the so-called micromagnetic standard problem 1. We demonstrate that for these parameters a diamond domain pattern is the lowest energy state that replaces cross-tie patterns favorable in larger elements. Only at smaller sizes does the originally envisaged Landau pattern form the ground state. The transition to high-remanence structures (or what would be comparable to a “single-domain” state) is found for lateral sizes that are an order of magnitude smaller than the benchmark parameters. The transitions among the different domain patterns become plausible in view of the energy of symmetric Néel walls in extended thin films. The features of the high-remanence structures can be derived from the principle of uniform charge distribution.