Electronic and Magnetic Structure of Possible Iron Based Superconductor BaFe2Se3

TL;DR

This paper uses first-principles calculations to analyze the electronic and magnetic properties of BaFe2Se3, comparing it with other iron-based superconductors, and predicts its magnetic structure and Neel temperature.

Contribution

It provides the first detailed electronic and magnetic structure analysis of BaFe2Se3, predicting its magnetic configuration and Neel temperature using LSDA calculations.

Findings

BaFe2Se3 is antiferromagnetic with T_N~250K.

The 'plaquettes' spin structure is more favorable.

Predicted Neel temperature for the preferred structure.

Abstract

We present results of LDA calculations (band structure, densities of states, Fermi surfaces) for possible iron based superconductor BaFe2Se3 (Ba123) in normal (paramagnetic) phase. Results are briefly compared with similar data on prototype BaFe2As2 and (K,Cs)Fe2Se2 superconductors. Without doping this system is antiferromagnetic with T_N^{exp}~250K and rather complicated magnetic structure. Neutron diffraction experiments indicated the possibility of two possible spin structures (antiferromagnetically ordered "plaquettes" or "zigzags"), indistinguishable by neutron scattering. Using LSDA calculated exchange parameters we estimate Neel temperatures for both spin structures within the molecular field approximation and show \tau_1 ("plaquettes") spin configuration to be more favorable than \tau_2 ("zigzags").