The electronic structure and magnetism of LiFeO$_{ 2}$Fe$_{ 2}$Se$_{ 2}$ are investigated using the first-principle calculations. The ground state is N$\acute{ e}$el antiferromagnetic (AFM) Mott insulating state for Fe1 with localized magnetism in LiFeO$_{ 2}$ layer and striped AFM metallic state for Fe2 with itinerant magnetism in Fe$_{ 2}$Se$_{ 2}$ layer, accompanied with a weak interlayer AFM coupling between Fe1 and Fe2 ions, resulting in a coexistence of localized and itinerant magnetism. Moreover, the layered LiFeO$_{ 2}$ is found to be more than an insulating block layer but responsible for enhanced AFM correlation in Fe$_{ 2}$Se$_{ 2}$ layer through the interlayer magnetic coupling. The interplay between the magnetisms of Fe1 and Fe2 introduces a control mechanism for spin fluctuations associated with superconductivity in iron-based superconductors.
Categories: cond-mat.supr-con cond-mat.str-el