Pnicogen-bridged antiferromagnetic superexchange interactions in iron pnictides

TL;DR

This paper investigates the magnetic interactions in iron-pnictide superconductors, emphasizing the role of arsenic-bridged superexchange interactions, supported by first-principles calculations on various compounds.

Contribution

It extends the understanding of magnetic interactions in iron-pnictides by analyzing arsenic-bridged superexchange mechanisms across different materials.

Findings

Identification of arsenic-bridged superexchange as key to magnetism

Prediction of antiferromagnetic order in LaFeAsO and FeTe

Analysis of magnetism's connection to superconductivity

Abstract

The first-principles electronic structure calculations made substantial contribution to study of high $T_c$ iron-pnictide superconductors. By the calculations, LaFeAsO was first predicted to be an antiferromagnetic semimetal, and the novel bi-collinear antiferromagnetic order was predicted for $\alpha$-FeTe. Moreover, based on the calculations the underlying mechanism was proposed to be Arsenic-bridged antiferromagnetic superexchange interaction between the next-nearest neighbor Fe moments. In this article, this physical picture is further presented and discussed in association with the elaborate first-principles calculations on LaFePO. The further discussion of origin of the magnetism in iron-pnictides and in connection with superconductivity is presented as well.