Dynamical reaction pathways in Eley-Rideal recombination of nitrogen from W(100) |
| |
Authors: | E Quintas-Sa?nchez P Larre?garay C Crespos L Martin-Gondre J Rubayo-Soneira J-C Rayez |
| |
Institution: | InSTEC, Ave. Salvador Allende esq. Luaces, 10600 La Habana, Cuba. |
| |
Abstract: | The scattering of atomic nitrogen over a N-pre-adsorbed W(100) surface is theoretically described in the case of normal incidence off a single adsorbate. Dynamical reaction mechanisms, in particular Eley-Rideal (ER) abstraction, are scrutinized in the 0.1-3.0?eV collision energy range and the influence of temperature on reactivity is considered between 300 and 1500 K. Dynamics simulations suggest that, though non-activated reaction pathways exist, the abstraction process exhibits a significant collision energy threshold (0.5 eV). Such a feature, which has not been reported so far in the literature, is the consequence of a repulsive interaction between the impinging and the pre-adsorbed nitrogens along with a strong attraction towards the tungsten atoms. Above threshold, the cross section for ER reaction is found one order of magnitude lower than the one for hot-atoms formation. The abstraction process involves the collision of the impinging atom with the surface prior to reaction but temperature effects, when modeled via a generalized Langevin oscillator model, do not affect significantly reactivity. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|