Shaping the morphology of oxide nanolayers is of paramount importance in tailoring their physical and chemical properties. Here, the influence of a two dimensional graphene buffer layer on the growth of Fe oxide has been investigated by comparing the oxide deposition on a Ni(111) and a graphene/Ni(111) substrate. Scanning tunneling microscopy images acquired at a mesoscopic scale indicate that Fe oxide grows layer-by-layer on the bare Ni(111) surface, while the nucleation of three-dimensional clusters is induced by graphene. Atomically resolved images reveal that Fe oxide adopts an in-plane lattice constant similar to that of the FeO(111) surface when deposited on Ni(111) and graphene/Ni(111), indicating in both cases, a weak interaction between the overlayer and the substrate. Accordingly, it is suggested that the different growth mode is mainly driven by the graphene-induced lowering of the substrate surface free energy.

3-dimensional nucleation of Fe oxide induced by a graphene buffer layer

Lodesani, Alessandro;Picone, Andrea;Brambilla, Alberto;Finazzi, Marco;Duo, Lamberto;Ciccacci, Franco
2020

Abstract

Shaping the morphology of oxide nanolayers is of paramount importance in tailoring their physical and chemical properties. Here, the influence of a two dimensional graphene buffer layer on the growth of Fe oxide has been investigated by comparing the oxide deposition on a Ni(111) and a graphene/Ni(111) substrate. Scanning tunneling microscopy images acquired at a mesoscopic scale indicate that Fe oxide grows layer-by-layer on the bare Ni(111) surface, while the nucleation of three-dimensional clusters is induced by graphene. Atomically resolved images reveal that Fe oxide adopts an in-plane lattice constant similar to that of the FeO(111) surface when deposited on Ni(111) and graphene/Ni(111), indicating in both cases, a weak interaction between the overlayer and the substrate. Accordingly, it is suggested that the different growth mode is mainly driven by the graphene-induced lowering of the substrate surface free energy.
THE JOURNAL OF CHEMICAL PHYSICS
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11311/1130816
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