Electronic structure and magnetic properties for iron-selenide KFe2Se2 are studied by first-principles calculations. The ground state is stripe-like antiferromagnetic with calculated 2.26 μB magnetic moment on Fe atoms; and the J1, J2 coupling strengths are calculated to be 0.038 eV and 0.029 eV. The states around EF are dominated by the Fe-3d orbitals which hybridize noticeably to the Se-4p orbitals. While the band structure of KFe2Se2 is similar to a heavily electron-doped BaFe2As2 or FeSe system, the Fermi surface of KFe2Se2 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 KFe2Se2 could be regarded as an electron over-doped 11 system with possible local moment magnetism.
@article{arxiv.1012.5621,
title = {Electronic Structure of KFe$_2$Se$_2$ from First Principles Calculations},
author = {Chao Cao and Jianhui Dai},
journal= {arXiv preprint arXiv:1012.5621},
year = {2015}
}
Comments
accepted by Chinese Physics Letter, to appear as Chinese Physics Letter, Vol 28, page 057402 (2011)