Striped antiferromagnetic order and electronic properties of stoichiometric LiFeAs from first-principles calculations

TL;DR

This study uses first-principles calculations to analyze the magnetic and electronic properties of stoichiometric LiFeAs, revealing a striped antiferromagnetic order similar to other FeAs compounds and explaining the absence of magnetic phase transitions.

Contribution

First-principles calculations identify the magnetic ground state of LiFeAs and clarify the origin of its magnetic stability and lack of phase transition.

Findings

LiFeAs exhibits striped antiferromagnetic order similar to other FeAs compounds.

The tiny inter-layer spin coupling explains the absence of magnetic phase transition.

Calculated atomic positions agree well with experimental data.

Abstract

We investigate the structural, electronic, and magnetic properties of stoichiometric LiFeAs by using state-of-the-arts first-principles method. We find the magnetic ground-state by comparing the total energies among all the possible magnetic orders. Our calculated internal positions of Li and As are in good agreement with experiment. Our results show that stoichiometric LiFeAs has almost the same striped antiferromagnetic spin order as other FeAs-based parent compounds and tetragonal FeSe do, and the experimental fact that no magnetic phase transition has been observed at finite temperature is attributed to the tiny inter-layer spin coupling.