Magnetocrystalline Anisotropy of D0$_{3}{\hbox{-Fe}}_{3}$ Si From First-Principles Study

First-principles calculations on the magnetocrystalline anisotropy (MCA) of Fe
₃
Si have been investigated by means of the all-electron full-potential linearized augmented plane-wave method within general gradient approximation. Calculated MCA constants k
₁
and k
₂
are 0.33 and -0.17 μeV/Fe, respectively, in consistency with experiment. Easy magnetization axis along the (100) direction was found in a cubic Fe
₃
Si compared to the (110) and (111) magnetization axes. We investigated the strain-dependent MCA energy under tetragonal distortion to predict magnetic easy axis when Fe
₃
Si grows on a substrate. The calculated MCA energies explain quite well experimental results on Fe
₃
Si systems on GaAs(001) and MgO(001). Magnetic moments, elastic constants, and magnetostriction were found to be quite consistent with experiments.