| Autor: |
Beatty, John, Cheng, Tao, Cao, Yuan, Driver, M. Sky, Goddard, William A., III, Kelber, Jeffry A. |
| Jazyk: |
angličtina |
| Rok vydání: |
2016 |
| Popis: |
We report direct grown strongly adherent graphene on Co_3O_4(111) by Carbon molecular beam epitaxy (MBE) at 850 K and DFT findings that the first graphene layer is reconstructed to fit the Co_3O_4 surface, while subsequent layers retain normal graphene structure. This adherence to the Co_3O_4 structure results from partial bonding of half the carbons to top oxygen of the substrate. This structure is validated by X-ray photoelectron spectroscopy and low energy electron diffraction studies, showing layer-by-layer graphene growth with ~ 0.08 electrons/carbon atom transferred to the oxide from the first graphene layer, in agreement with DFT. In contrast, C MBE on Cr_2O_3(0001) yields only graphite formation at 700 K, with C desorption above 800 K. For Cr_2O_3 DFT finds no strong bonding to the surface, with charge transfer is away from the oxide. Thus strong graphene-to-oxide charge transfer aids nucleation of graphene on incommensurate oxide substrates. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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