Aggregation of ferromagnetic and paramagnetic atoms at edges of graphenes and graphite

TL;DR

This study investigates how ferromagnetic and paramagnetic metals form nanowires and gaps along graphene and graphite edges during thermal evaporation, revealing magnetic properties influence edge nanostructure formation.

Contribution

It demonstrates that ferromagnetic and paramagnetic metals create unique edge nanostructures on graphene and graphite, a behavior affected by external magnetic fields, which is a novel observation.

Findings

Ferromagnetic and paramagnetic metals form nanowires and gaps at edges.

Diamagnetic metals do not form these edge features.

External magnetic fields suppress the edge nanostructures for ferromagnetic and paramagnetic metals.

Abstract

In this work, we report that when ferromagnetic metals (Fe, Co and Ni) are thermally evaporated onto n-layer graphenes and graphite, a metal nanowire and adjacent nanogaps can be found along the edges regardless of its zigzag or armchair structure. Similar features can also be observed for paramagnetic metals, such as Mn, Al and Pd. Meanwhile, metal nanowires and adjacent nanogaps can not be found for diamagnetic metals (Au and Ag). An external magnetic field during the evaporation of metals can make these unique features disappear for ferromagnetic and paramagnetic metal; and the morphologies of diamagnetic metal do not change after the application of an external magnetic field. We discuss the possible reasons for these novel and interesting results, which include possible one dimensional ferromagnets along the edge and edge-related binding energy.