Emergence of noncollinear magnetic ordering in small magnetic clusters: Mn$_n$ and As@Mn$_n$

TL;DR

This study uses first-principles calculations to explore how small manganese clusters and arsenic-doped manganese clusters develop noncollinear magnetic orderings, revealing size-dependent magnetic ground states and effects of doping.

Contribution

It demonstrates the emergence of noncollinear magnetic ground states in clusters with more than five atoms and highlights the impact of arsenic doping on binding energy and magnetic moments.

Findings

Noncollinear magnetic states appear for clusters with n ≥ 6.

Doping with arsenic enhances binding energy.

Magnetic moments are reduced in As@Mnₙ clusters.

Abstract

Using first-principles density functional calculations, we have studied the magnetic ordering in pure Mn$_n$ ($n=2-$10, 13, 15, 19) and As@Mn$_n$ ($n=1-$10) clusters. Although, for both pure and doped manganese clusters, there exists many collinear and noncollinear isomers close in energy, the smaller clusters with $n\leqslant$5 have collinear magnetic ground state and the emergence of noncollinear ground states is seen for $n\geqslant$6 clusters. Due to strong $p-d$ hybridization in As@Mn$_n$ clusters, the binding energy is substantially enhanced and the magnetic moment is reduced compared to the corresponding pure Mn$_n$ clusters.