Anomalous Magnetic Properties of Rh$_13$ Clusters

TL;DR

This study investigates the electronic and magnetic properties of Rh$_{13}$ clusters with high symmetry, revealing an anomalously small magnetic moment consistent with experiments, and explores the interactions within the cluster using advanced computational methods.

Contribution

The paper provides a detailed computational analysis of Rh$_{13}$ clusters' magnetic properties, introducing an energy parameter to explain anomalies and guide density functional calculations.

Findings

Ground state is icosahedral with 15μ_B magnetic moment.

Magnetic interactions are mixed ferromagnetic and antiferromagnetic.

Energy parameter helps explain anomalous magnetic behavior.

Abstract

Electronic structures of 13-atom Rh clusters with three possible high-symmetry geometries are studied using the discrete-variational local-spin-density-functional method. The ground state is found to be the icosahedral structure, and a total magnetic moment of 15$\mu_B$ is obtained for the cluster. This value is anomalously smaller than those for clusters with lower symmetries, but in agreement with recent experiments. The magnetic interactions between the central and surface atoms of the cluster are {\it not} fully ferromagnetic, and a small amount of antiferromagnetic interactions is found to be mixed in. An energy parameter is introduced to explain the anomalous magnetic properties, which is found to be also useful for judging whether some techniques can or must be used in the local-spin-density-functional calculations.