Crystal, magnetic, and electronic structures, and properties of new BaMnPnF (Pn = As, Sb, Bi)

TL;DR

This study synthesizes and characterizes new BaMnPnF compounds, revealing their crystal structures, semiconducting properties, and antiferromagnetic order, with detailed insights into their electronic and magnetic behaviors.

Contribution

The paper reports the first synthesis and comprehensive analysis of BaMnPnF compounds with Pn = As, Sb, Bi, including their structure, electronic, and magnetic properties.

Findings

BaMnPnF compounds crystallize in tetragonal ZrCuSiAs-type structure.

They are semiconductors with varying band gaps, from 0.003 eV to 0.73 eV.

BaMnAsF and BaMnSbF exhibit G-type antiferromagnetic order below 338 K and 272 K, respectively.

Abstract

New fluoropnictides BaMnPnF with Pn = As, Sb, Bi, are synthesized by stoichiometric reaction of elements with BaF\_2. The compounds crystallize in the tetragonal P4/nmm (No. 129, Z = 2) space group, with the ZrCuSiAs-type structure, as indicated by single crystal and powder X-ray diffraction results. Electrical resistivity results indicate that Pn = As, Sb, and Bi are semiconductors with band gaps of E\_g = 0.73 eV, E\_g = 0.48 eV and E\_g = 0.003 eV, respectively. Powder neutron diffraction reveals a G-type antiferromagnetic order below T\_N = 338(1) K for Pn = As, and below T\_N = 272(1) K for Pn = Sb. Magnetic susceptibility increases with temperature above 100 K for all the materials. Density functional calculations also find semiconducting antiferromagnetic compounds with strong in-plane and weaker out-of-plane exchange coupling that may result in non-Curie Weiss behavior above T\_N. There is strong covalency between Mn and pnictogen elements. The ordered magnetic moments are 3.65(5) {\mu}B/Mn for Pn = As, and 3.66(3) {\mu}B/Mn for Pn = Sb at 4 K, as refined from neutron diffraction experiments.