Magnetization of a two-component Stoner-Wohlfarth particle

The free energy of an arbitrary two-component Stoner-Wohlfarth particle is derived and general criteria for stable states of magnetization are established. Hysteretic properties of coaxial prolate spheroids composed of γ-Fe
2
O
3
coated iron particles are calculated numerically and the specific extension to epitaxial cobalt ferrite γ-Fe
2
O
3
particles amongst other two-component systems is indicated.