Graphene−iron(II) phthalocyanine hybrid systems for scalable molecular spintronics

Abstract

Graphene−transition metal phthalocyanine (G− MPc) hybrid systems constitute promising platforms for densely packed single-molecule magnets (SMMs). Here, we selected iron(II) phthalocyanine (FePc) and investigated its interaction with pristine and defective graphene layers employing density functional theory. Our calculations indicate that through proper dehydrogenation of the benzol rings in the FePc molecule, its adsorption to graphene is thermodynamically favorable. In general, the presence of anchoring sites on the graphene layer, i.e., point defects, additionally facilitates the adsorption of FePc, allowing one to achieve high density of SMMs per unit area. Using the combination of group theory, ligand field splitting, and the calculated PBE0 Kohn-Sham eigenvalue spectrum, we resolved the electronic structure and predicted the spin states of both isolated FePc and G−FePc hybrid systems. Regardless of the adsorption site and the number of removed hydrogen atoms from the benzol rings of FePc, the magnetic moment of the SMM remains unchanged with respect to the free FePc. These results should mediate a successful synthesis of densely packed G−MPc systems and may open up a new avenue in designing scalable graphene−SMM systems for spintronics applications.