Edge and Width Dependent Electronic Properties of Nanoribbons of Manganese Oxide

TL;DR

This study investigates the structural, magnetic, and electronic properties of MnO nanoribbons, revealing edge-dependent electronic behavior and magnetic orderings, with potential implications for nanoelectronic applications.

Contribution

It provides a comprehensive first-principles analysis of MnO nanoribbons, highlighting edge effects on electronic and magnetic properties, which were not previously characterized.

Findings

Zigzag nanoribbons are metallic.

Armchair nanoribbons are semiconductors.

AFM order perpendicular to nanoribbon growth is energetically favorable.

Abstract

In the present work, the structural, magnetic, and electronic properties of the two- and one-dimensional honeycomb structures of recently synthesized MnO [Zhang et al. Nat. Commun., 20, 1073-1078 (2021)] are investigated by using first principles calculations. Our calculations show that the single layer 2D MnO crystal has a degenerate antiferromagnetic (AFM) ground state and a relatively less favorable ferromagnetic (FM) state. In addition, magnetic anisotropy calculations unveil that the easy-axis direction for magnetism originating from unpaired electron states in manganese atoms is normal to the crystal plane. Electronically, while the FM-MnO is a direct semiconductor with a narrow bandgap, AFM phases display large indirect bandgap semiconducting behavior. Moreover, calculations on nanoribbons of MnO reveal that zigzag edged ribbons display metallic bahavior, whereas armchair edged nanoribbons are semiconductors. Magnetically, for both zigzag- or armchair-edged nanoribbons, AFM order perpendicular to the nanoribbon growth direction is found to be favorable over the other AFM and FM orders. Moreover, depending on the edge symmetry and ribbon width, forbidden band gap values of nanoribbons display distinct family behaviors.