3 research outputs found
Striped antiferromagnetism and electronic structures of SrFeAsF and their implications
We investigate structural, magnetic, and electronic properties of SrFeAsF as
a new parent for superconductors using state-of-the-art density-functional
theory method. Calculated results show that striped antiferromagnetic order is
the magnetic ground state in the Fe layer and interlayer magnetic interaction
is tiny. Calculated As and Sr positions are in agreement with experiment. There
are only two uniaxially-dispersed bands near the Fermi level. The valent charge
is mainly in the Fe and F layers, and the magnetic moment is confined to the Fe
atoms. Inter-Fe-spin couplings is due to superexchange through As atoms. These
are useful to understanding the SrFeAsF and should have helpful implications to
doped samples.Comment: 5 pages with figures include
Distorted magnetic orders and electronic structures of tetragonal FeSe from first-principles
We use the state-of-the-arts density-functional-theory method to study
various magnetic orders and their effects on the electronic structures of the
FeSe. Our calculated results show that, for the spins of the single Fe layer,
the striped antiferromagnetic orders with distortion are more favorable in
total energy than the checkerboard antiferromagnetic orders with tetragonal
symmetry, which is consistent with known experimental data, and the inter-layer
magnetic interaction is very weak. We investigate the electronic structures and
magnetic property of the distorted phases. We also present our calculated spin
coupling constants and discuss the reduction of the Fe magnetic moment by
quantum many-body effects. These results are useful to understand the
structural, magnetic, and electronic properties of FeSe, and may have some
helpful implications to other FeAs-based materials