Dependence of Magnetic Anisotropy Energy on c/a Ratio of X2Fe14B (X = Y, Pr, Dy)

Rare earth-iron-boron permanent magnet materials exhibit large values of magnetocrystalline anisotropy. We have studied the dependence of the magnetization (moments) and the anisotropy energy on the change of the lattice parameter ratio c/a . The calculations were on the basis of the density functional theory, and were carried out with the WIEN2k code, a linearized augmented plane wave method. The spin-orbit coupling was also included to consider the relativistic effects concerning the 3d-4f interaction.