Electronic structure of vacancy-ordered iron-selenide K$_{0.5}$Fe$_{1.75}$Se$_2$

Chao Cao; Fuchun Zhang

doi:10.1103/PhysRevB.87.161105

paper

Electronic structure of vacancy-ordered iron-selenide K $_{0.5}$ Fe $_{1.75}$ Se $_{2}$

arXiv:1301.7655 · doi:10.1103/PhysRevB.87.161105

Abstract

The electronic structure of the vacancy-ordered K $_{0.5}$ Fe $_{1.75}$ Se $_{2}$ iron-selenide compound (278 phase) is studied using the first-principles density functional method. The ground state of the 278 phase is stripe-like antiferromagnetic, and its bare electron susceptibility shows a large peak around $(π, π)$ in the folded Brillouin zone. Near Fermi level, the density of states are dominated by the Fe-3d orbitals, and both electron-like and hole-like Fermi surfaces appear in the Brillouin zone. Unfolded band structure shows limited similarities to a hole doped 122 phase. With 0.1e electron doping, the susceptibility peak is quickly suppressed and broadened; while the two-dimensionality of the electron-like Fermi surfaces are greatly enhanced, resulting in a better nesting behavior. Our study should be relevant to the recently reported superconducting phase K $_{0.5 + x}$ Fe $_{1.75 + y}$ Se $_{2}$ with both $x$ and $y$ very tiny.

Updated with correct susceptibility data figures

Electronic structure of vacancy-ordered iron-selenide K0.5​Fe1.75​Se2​

Abstract

References in corpus (6)

Electronic structure of vacancy-ordered iron-selenide K $_{0.5}$ Fe $_{1.75}$ Se $_{2}$