ALIGNED 2-PHASE MAGNETS - PERMANENT MAGNETISM OF THE FUTURE (INVITED)

Micromagnetic calculations are used to investigate coercivity and energy products of magnets consisting of an aligned hard-magnetic skeleton phase and a soft-magnetic phase with high saturation magnetization. Compared to the present-day theoretical limit of 516 kJ/m3 for single-phase Nd 2Fe14B, the energy product in suitable nanostructured Sm2Fe17N3/Fe65Co35 composites is predicted to be as high as 1090 kJ/m3. The influence of the skeleton's texture and shape is discussed, and aligned nanocrystalline two-phase magnets are compared with remanence-enhanced isotropic magnets. In particular, it is shown how the nucleation-based analytical approach breaks down in the isotropic limit. Finally, we outline conceivable processing methods and discuss potential applications of"megajoule" magnets.