BaFe2Se2O as an Iron-Based Mott Insulator with Antiferromagnetic Order

TL;DR

This paper reports the synthesis and characterization of BaFe2Se2O, a new iron-based compound that exhibits Mott insulating behavior and antiferromagnetic order, with insights into its electronic structure and magnetic interactions.

Contribution

It introduces BaFe2Se2O as a novel Mott insulator with antiferromagnetic order, supported by experimental synthesis, magnetic measurements, and theoretical calculations.

Findings

BaFe2Se2O is an insulator with AF transition at 240 K.

Band structure shows Fe 3d band narrowing leading to Mott behavior.

Strong in-plane AF exchange explains high magnetic susceptibility.

Abstract

A new compound with a quasi-two-dimensional array of FeSe3O tetrahedra and an orthorombic structure, namely BaFe2Se2O, has been successfully fabricated. Experimental results show that this compound is an insulator and has an antiferromagnetic (AF) transition at 240 K. Band structure calculation reveals the narrowing of Fe 3d bands near the Fermi energy, which leads to the localization of magnetism and the Mott insulating behavior. The large distances between the Fe atoms perhaps are responsible for the characters. Linear response calculation further indicates a strong in-plane AF exchange $J$, this can account for the enhanced magnetic susceptibility (which has a maximum at about 450 K) above the Neel temperature.