Writing the magnetic state with carbon monoxide

We devised a a scalable method for writing the magnetic state by electron-stimulated molecular dissociative adsorption on ultrathin cobalt grown on Re(0001). To do this, we expose the  film to carbon monoxide while irradiating the surface with an intense, micro-focused low energy electron beam. During irradiation, the CO molecules readily dissociate. This process, which is accompanied by the desorption of oxygen, favors the accumulation of carbon at the surface up to a coverage of one atomic layer. Most notably, we find that this overlayer can be converted to graphene upon a simple thermal treatment. As demonstrated by magnetic sensitive microscopy, the irradiated (graphene-covered) and non-irradiated (clean surface) regions exhibit out-of-plane and in-plane magnetic anisotropy, respectively. Our study provides a proof-of-principle that arbitrary magnetic

patterns can be lithographically grafted in cobalt by simply depositing surface carbon. Our fabrication protocol adds lateral control to spin reorientation transitions, permitting to tune the magnetic anisotropy within arbitrary regions of mesoscopic size. We envisage applications in the nano-engineering of graphene-spaced stacks exhibiting the desired magnetic state and properties.

Retrieve article

Magnetic patterning by electron beam assisted carbon lithography; P. Genoni, F. Genuzio, T.O. Menteş, B. Santos, A. Sala, C. Lenardi, A. Locatelli; ACS Applied Materials & Interfaces 10(32), 27178–27187 (2018); doi: 10.1021/acsami.8b07485.