Magnetic transitions of permalloy rings in hybrid devices

Fringe-field-induced local Hall magnetometry is applied to investigate microstructured NiFe rings. The semiconductor-based technique yields a high detection sensitivity of magnetic stray fields. This allows an accurate measurement of different magnetic configurations and their reversible and irreversible transitions. The corresponding spatial magnetic moment distribution is calculated by micromagnetic simulations. Additionally, the stray field of the simulated configurations and the resulting magnetic-force microscopy images are computed. The latter is compared to measurements and thus gives deeper insight into the understanding of magnetic configurations in rings and their modeling.