Unusual Structure and Magnetism in MnO Nanoclusters

TL;DR

This study explores the unique structural and magnetic properties of MnO nanoclusters, revealing size-dependent geometries and antiferromagnetic coupling, which differ from prior theoretical predictions and molecular magnet behaviors.

Contribution

It provides the first comprehensive density functional theory analysis showing unusual structures and magnetic properties in MnO clusters, challenging previous assumptions.

Findings

Small clusters are two-dimensional

Magnetic coupling is antiferromagnetic

Structures differ from Mn-based molecular magnets

Abstract

We report an unusual evolution of structure and magnetism in stoichiometric MnO clusters based on an extensive and unbiased search through the potential energy surface within density functional theory. The smaller clusters, containing up to five MnO units, adopt two-dimensional structures; and regardless of the size of the cluster, magnetic coupling is found to be antiferromagnetic in contrast to previous theoretical findings. Predicted structure and magnetism are strikingly different from the magnetic core of Mn-based molecular magnets, whereas they were previously argued to be similar. Both of these features are explained through the inherent electronic structures of the clusters.