Strain effects on the magnetic anisotropy of Y2Fe14B examined by first-principles calculations

We investigate strain effects on the magnetic anisotropy energy (MAE) and the magnetic moment of Y2Fe14B on the basis of density functional theory. We find that the MAE is significantly enhanced upon compression of the lattice. By applying second-order perturbation theory, the coupling among orbitals that is the most significant in enhancing the perpendicular magnetic anisotropy by the compression is identified to be the 3dx2−y2↓−3dxy↓ coupling at the Fe j2 site, thereby we emphasize importance of both the effect of the local density of states and the orbital couplings.