Magnetism of cobalt nanoclusters on graphene on iridium

TL;DR

This study investigates the structure and magnetic properties of cobalt nanoclusters on graphene/Ir(111), revealing minimal anisotropy in small clusters and potential magnetic coupling, using in situ microscopy and X-ray techniques.

Contribution

It provides new insights into the magnetic behavior of cobalt nanoclusters on graphene, highlighting the effects of cluster size and organization.

Findings

Small clusters exhibit almost no magnetic anisotropy.

Evidence suggests magnetic coupling between clusters.

Careful experimental procedures are necessary to prevent cluster damage.

Abstract

The structure and magnetic properties of Co clusters, comprising from 26 to 2700 atoms, self-organized or not on the graphene/Ir(111) moir\'e, were studied in situ with the help of scanning tunneling microscopy and X-ray magnetic circular dichroism. Surprisingly the small clusters have almost no magnetic anisotropy. We find indication for a magnetic coupling between the clusters. Experiments have to be performed carefully so as to avoid cluster damage by the soft X-rays.