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Detection of hydrogen using graphene.

Ehemann RC, Krstić PS, Dadras J, Kent PR, Jakowski J - Nanoscale Res Lett (2012)

Bottom Line: Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV.Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, TN, 37130, USA. rce2g@mtmail.mtsu.edu.

ABSTRACT
Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV. Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

No MeSH data available.


Related in: MedlinePlus

Potential energy of the H-graphene interaction at canonical points in the lattice. As calculated in DFTB (solid), AIREBO (single dash), and REBO (double dash).
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Figure 10: Potential energy of the H-graphene interaction at canonical points in the lattice. As calculated in DFTB (solid), AIREBO (single dash), and REBO (double dash).

Mentions: Figure 10 shows a comparison of the refitted [22] AIREBO and REBO H-graphene potentials with that of SCC-DFTB shown in Figure 2. The CMD potentials were calculated using a 480-atom graphene cluster, i.e., no periodic boundary conditions. All three potentials display a well near 1.2 Å for incidence upon a lattice carbon, and the subsequent repulsive barriers agree well as they are all fit to ZBL [22]. However, REBO and AIREBO predict 0.5 and 1.0 eV barriers, respectively, before the potential wells. As these barriers are not present in the SCC-DFTB potential, it is expected that REBO and AIREBO result in different dynamics at low-energy bombardment. The dissimilarities are even more distinct for the other positions in the lattice. AIREBO predicts a potential barrier of over 20 eV, peaking at about 1.35 Å, for incidence on the C-C bond center. Neither DFTB nor REBO agree with this barrier, which is produced by the long-range Lennard-Jones terms in AIREBO, since the AIREBO and REBO results are indistinguishable at distances less than 1 Å. Another peak of 20 eV height is found at z = 0 for AIREBO and REBO, only 2 eV higher than the corresponding SCC-DFTB curve. REBO is consistently 2 to 5 eV more repulsive than DFTB, but qualitatively very similar. The most distinctive difference between these three potentials is their treatment of the graphene π-orbitals. Clearly, the AIREBO Lennard-Jones interactions coming from the six adjacent carbons produce a potential barrier at the graphene hexagon center that is more than 60 eV (525%) higher than the potential in its predecessor, which is in turn roughly 10 eV (380%) higher than DFTB. The REBO potentials clearly agree much more with the DFTB calculations than those of AIREBO, which indicates that the Lennard-Jones interactions which produce the observed potential barriers likely overestimate the hydrogen-graphene interaction.


Detection of hydrogen using graphene.

Ehemann RC, Krstić PS, Dadras J, Kent PR, Jakowski J - Nanoscale Res Lett (2012)

Potential energy of the H-graphene interaction at canonical points in the lattice. As calculated in DFTB (solid), AIREBO (single dash), and REBO (double dash).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369821&req=5

Figure 10: Potential energy of the H-graphene interaction at canonical points in the lattice. As calculated in DFTB (solid), AIREBO (single dash), and REBO (double dash).
Mentions: Figure 10 shows a comparison of the refitted [22] AIREBO and REBO H-graphene potentials with that of SCC-DFTB shown in Figure 2. The CMD potentials were calculated using a 480-atom graphene cluster, i.e., no periodic boundary conditions. All three potentials display a well near 1.2 Å for incidence upon a lattice carbon, and the subsequent repulsive barriers agree well as they are all fit to ZBL [22]. However, REBO and AIREBO predict 0.5 and 1.0 eV barriers, respectively, before the potential wells. As these barriers are not present in the SCC-DFTB potential, it is expected that REBO and AIREBO result in different dynamics at low-energy bombardment. The dissimilarities are even more distinct for the other positions in the lattice. AIREBO predicts a potential barrier of over 20 eV, peaking at about 1.35 Å, for incidence on the C-C bond center. Neither DFTB nor REBO agree with this barrier, which is produced by the long-range Lennard-Jones terms in AIREBO, since the AIREBO and REBO results are indistinguishable at distances less than 1 Å. Another peak of 20 eV height is found at z = 0 for AIREBO and REBO, only 2 eV higher than the corresponding SCC-DFTB curve. REBO is consistently 2 to 5 eV more repulsive than DFTB, but qualitatively very similar. The most distinctive difference between these three potentials is their treatment of the graphene π-orbitals. Clearly, the AIREBO Lennard-Jones interactions coming from the six adjacent carbons produce a potential barrier at the graphene hexagon center that is more than 60 eV (525%) higher than the potential in its predecessor, which is in turn roughly 10 eV (380%) higher than DFTB. The REBO potentials clearly agree much more with the DFTB calculations than those of AIREBO, which indicates that the Lennard-Jones interactions which produce the observed potential barriers likely overestimate the hydrogen-graphene interaction.

Bottom Line: Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV.Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Astronomy, Middle Tennessee State University, Murfreesboro, TN, 37130, USA. rce2g@mtmail.mtsu.edu.

ABSTRACT
Irradiation dynamics of a single graphene sheet bombarded by hydrogen atoms is studied in the incident energy range of 0.1 to 200 eV. Results for reflection, transmission, and adsorption probabilities, as well as effects of a single adsorbed atom to the electronic properties of graphene, are obtained by the quantum-classical Monte Carlo molecular dynamics within a self-consistent-charge-density functional tight binding formalism We compare these results with those, distinctly different, obtained by the classical molecular dynamics.PACS: 61.80.Az, 61.48.Gh, 61.80.Jh, 34.50.Dy.

No MeSH data available.


Related in: MedlinePlus