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arXiv · 1012.5621

Electronic Structure of KFe$_2$Se$_2$ from First Principles Calculations

Chao Cao·Jianhui Dai
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Abstract

Electronic structure and magnetic properties for iron-selenide KFe$_2$Se$_2$ are studied by first-principles calculations. The ground state is stripe-like antiferromagnetic with calculated 2.26 $μ_B$ magnetic moment on Fe atoms; and the $J_1$, $J_2$ coupling strengths are calculated to be 0.038 eV and 0.029 eV. The states around $E_F$ are dominated by the Fe-3d orbitals which hybridize noticeably to the Se-4p orbitals. While the band structure of KFe$_2$Se$_2$ is similar to a heavily electron-doped BaFe$_2$As$_2$ or FeSe system, the Fermi surface of KFe$_2$Se$_2$ is much closer to \fs11 system since the electron sheets around $M$ is symmetric with respect to $x$-$y$ exchange. These features, as well as the absence of Fermi surface nesting, suggest that the parental KFe$_2$Se$_2$ could be regarded as an electron over-doped 11 system with possible local moment magnetism.

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Chao Cao, Jianhui Dai. 2011-03-20. Electronic Structure of KFe$_2$Se$_2$ from First Principles Calculations. https://doi.org/10.1088/0256-307x%2F28%2F5%2F057402

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