Magnetization reversal of thin Fe triangular rings

We have investigated the magnetization reversal of two regular arrays of Fe triangular microwire rings (base 7.3 mu m and 2.8 mu m, periodicity 11.5 mu m and 5.6 mu m, respectively) using the magneto-optical Kerr effect in vector-MOKE and Bragg-MOKE configuration. The measurements are compared with the results of micromagnetic simulations, which allow a detailed interpretation of the experimental data. We find that the magnetization reversal in an external magnetic field depends on the size of the triangles. Domain formation is more pronounced in the large than in the small triangular rings, and micromagnetic simulations show a vortex state in the small triangular rings. (c) 2006 Elsevier Ltd. All rights reserved.