Effects of iron substitution on magnetic properties of SmCo6.8 xFexHf0.2compounds

The effects of iron substitution on the crystal structure and magnetic properties of SmCo 6.8− x Fe x Hf 0.2 ( x = 0.1, 0.3, 0.5, and 0.7) compounds were investigated by means of x-ray powder diffraction and magnetic measurements. The as-cast SmCo 6.8− x Fe x Hf 0.2 compounds crystallize in the TbCu 7 -type structure with the space group P 6/ mmm . The lattice parameters a and c increase with the Fe content. The SmCo 6.8− x Fe x Hf 0.2 compounds exhibit ferromagnetic order with a strong room temperature uniaxial magnetocrystalline anisotropy. The Curie temperature and saturation magnetization increase with the Fe content. The magnetic anisotropy field of the compounds reaches a maximum value at x = 0.5. The anomalous concentration dependence of the anisotropy field is explained by considering the contribution of individual site anisotropy in combination with the preferential occupation of 3d ions on different sites.