Theory of charge exchange in the scattering of molecular ions from simple metals

Imke, U.; Snowdon, K.J.; Heiland, W.

doi:10.1103/physrevb.34.41

Cited by 54 publications

(19 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(3) Both experimental data 28,29 and results of the calculations [30][31][32] are consistent with the conclusion that the rate of the dissociative neutralization is greater than 10 14 s -1 . Consequently, the decay of the molecules occurs on the initial part of the scattering trajectory before the turning point.…”

Section: Analytical Calculations Of High-energy Tailssupporting

confidence: 82%

“…[30][31][32] Because we are interested in the energy spectra of scattered H atoms, we neglect the former possibility and introduce the rate of the electron capture into the triplet state as where is the angle between the molecular axis and the perpendicular to the surface. This dependence was found in first principles calculation [30][31][32] to be a good approximation for H 2 + neutralization on Al for not too small molecule-metal separation distances. We used the same parameters for the H 2 + -Ag system as obtained for H 2 + -Al in ref 31. On each integration step, a decision of whether neutralization occurred or not is made according to the probability P ) exp(-W∆t), where ∆t is the integration step.…”

Section: Molecular Dynamics Simulationsmentioning

confidence: 99%

See 1 more Smart Citation

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces

et al. 2002

View full text Add to dashboard Cite

Energy distributions of H atoms resulting from grazing scattering of H 2 + from metal surfaces are calculated analytically and by using classical trajectories simulations. The main mechanism leading to dissociation of H 2 + is proposed to be dissociative capture of an electron from the metal into the antibonding state of the H 2 molecule. It is shown that the energy distributions of scattered atoms yield information of both the molecular axis orientation and the vibrational excitation of the molecules during the scattering process.

show abstract

Section: Analytical Calculations Of High-energy Tailssupporting

confidence: 82%

Section: Molecular Dynamics Simulationsmentioning

confidence: 99%

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces

et al. 2002

View full text Add to dashboard Cite

show abstract

“…More precisely, we will analyze how these two processes affect secondary electron emission due to de-excitation of metastable molecules. Neutralization of molecular ions [22][23][24] will not be discussed. A particularly interesting case is the de-excitation of metastable N 2 ( 3 Σ + u ) because this molecule de-excites in two primary reaction channels 25,26 .…”

Section: Introductionmentioning

confidence: 99%

Pseudoparticle approach for charge-transferring molecule-surface collisions

2012

View full text Add to dashboard Cite

Based on a semi-empirical generalized Anderson-Newns model we construct a pseudo-particle description for electron emission due to de-excitation of metastable molecules at surfaces. The pseudo-particle approach allows us to treat resonant charge-transfer and Auger processes on an equal footing, as it is necessary when both channels are open. This is for instance the case when a metastable N2( 3 Σ + u ) molecule hits a diamond surface. Using non-equilibrium Green functions and physically motivated approximations to the self-energies of the Dyson equations we derive a system of rate equations for the probabilities with which the metastable N2( 3 Σ + u ) molecule, the molecular ground state N2( 1 Σ + g ), and the negative ion N − 2 ( 2 Πg) can be found in the course of the scattering event. From the rate equations we also obtain the spectrum of the emitted electron and the secondary electron emission coefficient. Our numerical results indicate the resonant tunneling process undermining the source of the Auger channel which therefore contributes only a few percent to the secondary electron emission.

show abstract

“…The experimental technique is described earlier [32] manner is somewhat more difficult, mainly because of uncertainties regarding the pertinent transition rate constants as functions of distance and orientation. Some knowledge is available [31] though, which will be used to include electronic transitions in a stochastic way in our future calculations.…”

Section: Classical Trajectories Calculationsmentioning

confidence: 99%

Scattering of Small Molecules at Surfaces

Heiland

Schlathölter

Vicanek

1995

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

The interaction of energetic molecules with surfaces is of interest for nuclear fusion experiments, for the erosion of space vehicles, and for the understanding of basic charge exchange phenomena between metal surfaces and molecules. For the latter reason experiments with hyperthermal molecules are also of interest for catalytic processes and for the functioning of solid state sensors. In many cases the interaction of molecules with surfaces is governed by charge exchange processes. An obvious case is the catalytic oxidation of CO at surfaces where a negative carbon dioxide species is identified as an intermediate of the reaction. Negative carbon dioxide species are also found in beam experiments. Their yield and the correlated dissociation probabilities show the expected dependencies on e.g. the coverage of the metal with alkali metal layers. In the case of hydrogen molecules the influence of alkali layers is quite different. In chemisorption experiments alkalis cause a decrease of the dissociative chemisorption of hydrogen. In our beam experiments an increase of the molecular survival with alkali coverage is found accordingly. The interpretation of the findings gives more detailed insight into the dissociation mechanisms of small molecules.

show abstract

Theory of charge exchange in the scattering of molecular ions from simple metals

Cited by 54 publications

References 35 publications

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces

Pseudoparticle approach for charge-transferring molecule-surface collisions

Scattering of Small Molecules at Surfaces

Contact Info

Product

Resources

About

Theory of charge exchange in the scattering of molecular ions from simple metals

Cited by 54 publications

References 35 publications

Dissociative Grazing Scattering of H2+ Ions from Metal Surfaces

Dissociative Grazing Scattering of H2+ Ions from Metal Surfaces

Pseudoparticle approach for charge-transferring molecule-surface collisions

Scattering of Small Molecules at Surfaces

Contact Info

Product

Resources

About

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces

Dissociative Grazing Scattering of H₂⁺ Ions from Metal Surfaces