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Graphene on ferromagnetic surfaces and its functionalization with water and ammonia.

Böttcher S, Weser M, Dedkov YS, Horn K, Voloshina EN, Paulus B - Nanoscale Res Lett (2011)

Bottom Line: In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented.ARPES and XAS data of the H2O (NH3)/graphene/Ni(111) system give an information regarding the kind of interaction between the adsorbed molecules and the graphene on Ni(111).The presented experimental data are compared with the results obtained in the framework of the DFT approach.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany. dedkov@fhi-berlin.mpg.de.

ABSTRACT
In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented. The results of adsorption on graphene/Ni(111) obtained in this study reveal the existence of interface states, originating from the strong hybridization of the graphene π and spin-polarized Ni 3d valence band states. ARPES and XAS data of the H2O (NH3)/graphene/Ni(111) system give an information regarding the kind of interaction between the adsorbed molecules and the graphene on Ni(111). The presented experimental data are compared with the results obtained in the framework of the DFT approach.

No MeSH data available.


Series of the ARPES spectra obtained on graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) along the Γ-K direction of the Brillouin zone. The amounts of water and ammonia were estimated as 0.5 of the ML. These data were collected with the photon energy of 75 eV.
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Figure 4: Series of the ARPES spectra obtained on graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) along the Γ-K direction of the Brillouin zone. The amounts of water and ammonia were estimated as 0.5 of the ML. These data were collected with the photon energy of 75 eV.

Mentions: Figure 4 shows a series of ARPES collected with the photon energy hν = 75 eV along the Γ-K direction of the Brillouin zone for the graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) systems. In all the series, one can clearly discriminate the dispersions of graphene π- and σ-derived states in the region below 2 eV of the binding energy as well as Ni 3d-derived states near EF. The binding energy difference of ≈2.4 eV for the π states and ≈1 eV for the σ states in the center of the Brillouin zone (in the Γ point) between graphite and graphene on Ni(111) is in good agreement with previously reported experimental and theoretical values [4,5,8], and it is explained by the differential strengths of hybridization for π and σ states in relation with Ni 3d states. The effect of hybridization between Ni 3d and graphene π states can be clearly demonstrated in the region around the K point of the Brillouin zone: (i) one of the Ni 3d bands at 1.50 eV changes its binding energy by ≈150 meV to larger binding energies when approaching the K point; (ii) a hybridization shoulder is visible in photoemission spectra which disperses from approximately 1.6 eV to the binding energy of the graphene π states at the K point. The full analysis of the electronic band structure and magnetic properties of the graphene/Ni(111) system were performed in Ref. [9].


Graphene on ferromagnetic surfaces and its functionalization with water and ammonia.

Böttcher S, Weser M, Dedkov YS, Horn K, Voloshina EN, Paulus B - Nanoscale Res Lett (2011)

Series of the ARPES spectra obtained on graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) along the Γ-K direction of the Brillouin zone. The amounts of water and ammonia were estimated as 0.5 of the ML. These data were collected with the photon energy of 75 eV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211271&req=5

Figure 4: Series of the ARPES spectra obtained on graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) along the Γ-K direction of the Brillouin zone. The amounts of water and ammonia were estimated as 0.5 of the ML. These data were collected with the photon energy of 75 eV.
Mentions: Figure 4 shows a series of ARPES collected with the photon energy hν = 75 eV along the Γ-K direction of the Brillouin zone for the graphene/Ni(111), H2O/graphene/Ni(111), and NH3/graphene/Ni(111) systems. In all the series, one can clearly discriminate the dispersions of graphene π- and σ-derived states in the region below 2 eV of the binding energy as well as Ni 3d-derived states near EF. The binding energy difference of ≈2.4 eV for the π states and ≈1 eV for the σ states in the center of the Brillouin zone (in the Γ point) between graphite and graphene on Ni(111) is in good agreement with previously reported experimental and theoretical values [4,5,8], and it is explained by the differential strengths of hybridization for π and σ states in relation with Ni 3d states. The effect of hybridization between Ni 3d and graphene π states can be clearly demonstrated in the region around the K point of the Brillouin zone: (i) one of the Ni 3d bands at 1.50 eV changes its binding energy by ≈150 meV to larger binding energies when approaching the K point; (ii) a hybridization shoulder is visible in photoemission spectra which disperses from approximately 1.6 eV to the binding energy of the graphene π states at the K point. The full analysis of the electronic band structure and magnetic properties of the graphene/Ni(111) system were performed in Ref. [9].

Bottom Line: In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented.ARPES and XAS data of the H2O (NH3)/graphene/Ni(111) system give an information regarding the kind of interaction between the adsorbed molecules and the graphene on Ni(111).The presented experimental data are compared with the results obtained in the framework of the DFT approach.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, 14195 Berlin, Germany. dedkov@fhi-berlin.mpg.de.

ABSTRACT
In this article, an angle-resolved photoelectron spectroscopy (ARPES), X-ray absorption spectroscopy (XAS), and density-functional theory (DFT) investigations of water and ammonia adsorption on graphene/Ni(111) are presented. The results of adsorption on graphene/Ni(111) obtained in this study reveal the existence of interface states, originating from the strong hybridization of the graphene π and spin-polarized Ni 3d valence band states. ARPES and XAS data of the H2O (NH3)/graphene/Ni(111) system give an information regarding the kind of interaction between the adsorbed molecules and the graphene on Ni(111). The presented experimental data are compared with the results obtained in the framework of the DFT approach.

No MeSH data available.