Nucleation field and energy product of aligned two-phase magnets-progress towards the '1 MJ/m/sup 3/' magnet

The exchange hardening of nanostructured two-phase systems composed of an aligned hard phase and a soft phase with high magnetization is investigated using a micromagnetic approach, which accounts for interactions between the soft regions. For Sm/sub 2/Fe/sub 17/N/sub 3/(2.5 nm)/Fe/sub 65/Co/sub 35/(9 nm) multilayers, an energy product as high as 1 MJ/m/sup 3/ (120 MGOe) is predicted, with a rare-earth content of only 5 wt.%. Giant energy products may also be achieved in suitable cellular and disordered structures.<
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