High temperature magnetic behaviour of iron-based nanocrystalline alloys

After a presentation of structural aspects of iron-based nanocrystalline alloys, the magnetic behaviors of those two-phase magnetic structures are conceptually discussed at high temperatures as a function of the crystalline volumetric fraction, on the basis of the magnetic correlation length compared to the distances between crystalline grains. In addition, some results predicted by an approach based on Monte-Carlo simulation are then briefly presented: they show a qualitative agreement with experimental results. (Example materials include FINEMET (Fe-Cu-Nb-B-Si), NANOPERM (FeMB with M=Zr, Hf, Nb) and HITPERM-type alloys ((Fe,Co)-M-B-Cu with M=Zr, Hf, Nb)).