Ion Implantation Leading to Magnetism in Many-Layer Graphene

P-orbital magnetism observed in graphene is of interest both to fundamental physics and for its potential application in new classes of spintronic devices. In this talk, we will demonstrate how low energy ion bombardment of graphene with hydrogen can be used to manipulate defect type and concentration to induce room temperature ferromagnetism in layered graphene. SQUID magnetometry measurements show that it is possible to control the magnetic properties by varying the H energy and dose. In-situ x-ray diffraction shows that ion distribution leads to layer expansion and an increase in RMS height variations of the graphene layers. Neutron reflectivity reveals that implanted H ions remain in the sample after dosing via chemisorption. The relationship between these results and magnetometry measurements, which show that ion implantation leads to a ferromagnetic moment at room temperature, will be discussed.