Large magnetic anisotropy in Fe_{0.25}TaS_2

We present a first-principles study of the large magneto-crystalline anisotropy in the intercalated di-chalcogenide material \ce{Fe_{0.25}TaS_2}, investigated with the DFT+U approach. We verify a uniaxial magnetocrystalline anisotropy energy(MAE) of 15meV/Fe. in the material. We further analyze the dependence of MAE on the constituent elements and the effect of spin-orbit coupling. Contrary to conventional intuition, we find a small contribution to MAE due to strong spin-orbit coupling in the heavier element, Ta. We show that the electronic configuration, crystal field environment and correlational effects of the magnetic ion are more important.