Ab initio study of magnetism and interaction of graphene with the polar MnO(111) surface

Abstract

Simulation of graphene adsorption onto the oxygen-terminated polar manganese monoxide surface (111) was performed as a function of the hydrogen coverage based on the density functional theory. Local atomic reconstructions of the SLG/H:MnO(111) interface, and their thermodynamic, electronic and magnetic properties were methodically analyzed for different adsorption models. The bond lengths and the adsorption energy values were found for different reconstructions of the surface atomic structure in the SLG/H:MnO(111) systems, and the effects of graphene adsorption on the electronic spectrum of the SLG/H:MnO(111) interface were studied for its different reconstructions. The effective charges and the local magnetic moments on the carbon atoms and on the nearest-neighbor atoms were determined for the considered adsorption models. Charge transfer from the carbon atom to the nearest-neighbor atoms was found due to reconstruction of the local atomic and electronic structures, correlating with the interface hydrogenation rate. Hydrogenation of the interface surface provides for the p-n junction, turning graphene into an n-type semiconductor. The latter opens the way for creation of n-type graphene field-effect transistors. This paper predicts magnetism for zero-defect graphene adsorbed on the hydrogenated surface of MnO(111) magnetic insulator, and discusses the nature of such magnetism.