Nanoscale magnetic domains in mesoscopic dots: Micromagnetic investigation of magnetisation processes

We have undertaken micromagnetic calculations of domain configurations in submicron cobalt dots. Good agreement is shown between calculated and measured hysteresis loops as well as between calculated and domain patterns observed by magnetic force microscopy. It appears also that the nucleation mechanism in a formerly saturated sample depends strongly on dot thickness. These changes in the nucleation mechanism and in domain evolution with applied field are found to be responsible for the wide variety of magnetisation configurations observed at zero applied field.