Large magnetic anisotropy in Fe_{0.25}TaS_2

TL;DR

This study uses first-principles calculations to reveal the large uniaxial magnetocrystalline anisotropy in Fe_{0.25}TaS_2, emphasizing the roles of electronic configuration and crystal environment over spin-orbit coupling.

Contribution

It provides a detailed first-principles analysis of the origin of large magnetic anisotropy in Fe_{0.25}TaS_2, highlighting factors beyond spin-orbit coupling.

Findings

Magnetocrystalline anisotropy energy of 15 meV/Fe verified.

Electronic configuration and crystal field are key to MAE.

Spin-orbit coupling in Ta has a surprisingly small contribution.

Abstract

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.