Importance of energy transfer and lattice properties in H-atom association with the (111) surface of diamond

• Published in: Journal of physical chemistry (1952) Vol. 97; no. 39; pp. 9934 - 9941
• Main Authors: ACCARY, C, BARBARAT, P, HASE, W. L, HASS, K. C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 30-09-1993
• Subjects: 360600 > Other Materials; CARBON; CHEMICAL COATING; CHEMICAL REACTION KINETICS; CHEMICAL REACTIONS; CHEMICAL VAPOR DEPOSITION; Chemistry; CRYSTAL LATTICES; CRYSTAL STRUCTURE; DATA; DEPOSITION; DIAMONDS; DIFFERENTIAL EQUATIONS; DISSOCIATION; ELEMENTAL MINERALS; ELEMENTS; ENERGY TRANSFER; EQUATIONS; EQUATIONS OF MOTION; Exact sciences and technology; General and physical chemistry; HYDROGEN; INFORMATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KINETICS; MATERIALS SCIENCE; MINERALS; NONMETALS; NUMERICAL DATA; PARTIAL DIFFERENTIAL EQUATIONS; RADICALS; REACTION KINETICS; Solid-gas interface; SURFACE COATING 400201 > Chemical & Physicochemical Properties; Surface physical chemistry; SURFACE PROPERTIES; THEORETICAL DATA; Potential energy; Temperature; Chemical association; Hydrogen; Molecular dynamics method; Carbon Molecules; Theoretical study; Diamond; Crystal face; Inorganic compound; Surface structure; Statistical method; Vibrational frequency; Lattice dynamics; Medium effect; Gas solid interface; Potential surface; Classical trajectory; Energy transfer
• ISSN: 0022-3654; 1541-5740
• DOI: 10.1021/j100141a008

This paper reports the results of a classical trajectory study of the dynamics of H-atom association with a radical site on the (111) surface of diamond. The association dynamics are affected by the potential between the H-atom and radical site, nonbonded interactions between the H-atom and the surface of the lattice, and the lattice vibrational frequencies. The sensitivity of the association probability to the lattice frequencies suggests that in a complete theory for association the dynamics of energy transfer from H-atom relative translation to the lattice modes must be considered. As a result, a capture theory like transition-state theory is expected to overestimate the association rate constant. The trajectories also show that once the H-atom associates there is a negligible initial transient in the ensuing dissociation of this H-atom from the lattice. The trajectory results are found to be sensitive to the treatment of zero-point energy. A quasiclassical trajectory calculation as performed here, which includes lattice zero-point energy, is expected to give a larger abstraction/addition rate constant ratio for a H-atom interacting with a diamond surface than does a molecular dynamics calculation, which does not include lattice zero-point energy. 73 refs., 11 figs., 3 tabs.