Dynamics of Single Fe Atoms in Graphene Vacancies

Abstract

Focused electron beam irradiation has been used to create mono and divacancies in graphene within a defined area, which then act as trap sites for mobile Fe atoms initially resident on the graphene surface. Aberration-corrected transmission electron microscopy at 80 kV has been used to study the real time dynamics of Fe atoms filling the vacancy sites in graphene with atomic resolution. We find that the incorporation of a dopant atom results in pronounced displacements of the surrounding carbon atoms of up to 0.5 Å, which is in good agreement with density functional theory calculations. Once incorporated into the graphene lattice, Fe atoms can transition to adjacent lattice positions and reversibly switch their bonding between four and three nearest neighbors. The C atoms adjacent to the Fe atoms are found to be more susceptible to Stone-Wales type bond rotations with these bond rotations associated with changes in the dopant bonding configuration. These results demonstrate the use of controlled electron beam irradiation to incorporate dopants into the graphene lattice with nanoscale spatial control.

Direct in situ observations of single Fe atom catalytic processes and anomalous diffusion at graphene edges

“…The insertion of carbon atoms at the graphene edge through Fe highlights the catalytic properties of Fe at an atomic level. In this process, free carbon atoms in the vicinity diffuse through the assistance of the electron beam (7,31). Electrons accelerated through 80 kV can transfer up to 16 eV to a carbon atom and 3 eV to a single Fe atom (32).…”

A first-principles study of light non-metallic atom substituted blue phosphorene

“…Nevertheless, the major source of the magnetism in two systems is quite different. These fascinating phenomenon, in combination with the fact that the substitutional 2D materials has been artificially synthesis by many groups [47][48][49][50][51][52][53], can paves a new route at nanoscale for novel functionalities of optical and spintronics devices.…”

Dual doped monolayer and bilayer graphene: The case of 4p and 2p elements

“…Yet, theoretical calculations have shown that it is a very interesting 2D material [7,8,25,26]. Moving down in the periodic table, Se [27,28], Ni [29,30], Mn [30], Fe [31], Co [30], were embedded in the graphene plane. Interestingly, even heavy elements like U and Th [32] were employed to dope graphene.…”