Anisotropy energy of Y2Fe14B, Y2Co14B, Y2Fe14−xCoxB, and La2Co14B

The anisotropy energies of Y2Fe14B, Y2Co14B, Y2Fe14−xCoxB, and La2Co14B are discussed with reference to the band model. The energy bands exclusive and inclusive of the p bands in B are formulated in consideration of the spin‐orbit interaction and exchange splitting. The anisotropy constant K1 is estimated through the difference between the calculated electronic energies with the magnetization parallel to [001] and [100]. In Y2Fe14B, the calculated K1 is much the same as the experimental result, and in Y2Co14B, it agrees with the experimental result. In Y2Fe14−xCoxB, the calculated K1 inclusive of the p bands in B is much the same as the experimental result. Finally, the anisotropy energy of La2Co14B is discussed by taking into account the 4f bands just above the Fermi level.