The structural origin of induced magnetic anisotropy in α-Fe1−xSix (x=0.05-0.08) alloys

The atomic structure of α-Fe1−xSix (x=0.05-0.08) single crystals possessing of diffusion-related magnetic anisotropy was studied by X-ray diffraction method. It was found that local atomic structure is characterized by chemical ordering of B2-type in combination with order of a certain kind in the displacement of atoms from sites of an ideal crystal lattice. Pairs of B2 unit cells disposed along the easy magnetization axes 〈1 0 0〉 form anisotropic local distribution of atoms. After annealing in a DC saturating magnetic field or under stress loading, chains of the B2 cells mainly oriented along one of the easy axes, namely, those which make a minimum angle with the direction of external effect, become “frozen” and are the origin of the appearance and stability of the uniaxial anisotropy of bulk magnetic properties.