High energy product of surface modified soft-phase magnets

A soft-phase based heterostructure magnet has been analyzed with micromagnetics. Calculated energy product critically depends on the diameter of the inner soft-phase. The volume fraction of the hard-phase shell region providing the high coercivity is much less than the inner soft-phase region. It was proven, at least theoretically, that an energy product of 70 MGOe can easily be achieved for 100 /spl Aring/ diameter soft-phase materials.