Origin of the magnetic anisotropy induced by stress annealing in Fe-based nanocrystalline alloy

摘要

The dependence of the structural anisotropy of Fe-Si-B-Nb-Cu alloy on the applied stress during annealing has been studied by transmission x-ray diffraction. After crystallizing under stress, the Fe-Si nanocrystals show anisotropy in the lattice spacing of the (620) planes. Their elongations are proportional to the applied stress and show a linear correlation with the magnetic anisotropy energy, K_u. These results indicate that K_u originates from a magnetoelastic effect due to an elastic elongation of the Fe-Si phase constrained by the surrounding amorphous phase.