Synthesis, crystal and magnetic structure of iron selenide BaFe2Se3 with possible superconductivity at Tc=11K

TL;DR

This study synthesizes BaFe2Se3 single crystals, revealing their crystal and magnetic structures, and reports possible superconductivity at around 11K, with magnetic ordering similar to known iron-based superconductors.

Contribution

It provides the first detailed structural and magnetic characterization of BaFe2Se3 and suggests potential superconductivity at 11K, expanding understanding of iron selenide compounds.

Findings

BaFe2Se3 has orthorhombic structure with FeSe4 tetrahedra chains.

Long-range antiferromagnetic order develops below 240 K.

Superconductivity observed with Tc approximately 11 K.

Abstract

We report on synthesis of single crystals of BaFe2Se3 and study of their crystal and magnetic structures by means of synchrotron single crystal X-ray and neutron powder diffraction. The crystal structure has orthorhombic symmetry and consists of double chains of FeSe4 edge connected tetrahedra intercalated by barium. Below 240 K long range block-spin checkerboard antiferromagnetic (AFM) order is developed. The magnetic structure is similar to one observed in A0.8Fe1.6Se2 (A=K, Rb or Cs) superconductors. The crystals exhibit a transition to the diamagnetic state with an onset transition temperature of Tc ~11 K. Though we observe FeSe as an impurity phase (<0.8% mass fraction) the diamagnetism unlikely can be attributed to the FeSe-superconductor which has Tc\approx8.5K.