MAGNETIZATION REVERSAL OF COBALT-MODIFIED GAMMA-FE2O3 PARTICLES

A micromagnetic study of the effects of cobalt modification on the magnetization reversal of elongated γ-Fe2O3 particles is presented. Equilibrium states and irreversible switching are computed numerically. The undoped particle core is identified as the site for the initial irreversible processes. For certain material parameters this can lead to a core-reversed state. The enhancement and the saturation of the enhancement of the switching field are explained as a function of doping level. Extrapolation of the numerical results suggests that approximately one monolayer of cobalt-ferrite is sufficient to yield significant enhancement of the coercivity.