Kinetics of H2 desorption from crystalline C60

Abstract

The nonequilibrium diffusion of H2 within crystalline C60 is examined by monitoring the outgassing of H2 from C60 powders. Results show that the desorption-lifetime decreases dramatically with increasing H2 concentration. Kinetic Monte Carlo simulations indicate that diffusion occurs by H2 molecules hopping between interstitial octahedral sites via an energetically unstable intermediary tetrahedral site. This diffusion is greatly enhanced by the presence of dimers in which two H2 molecules briefly occupy the same octahedral site. The abundance of dimers increases with H2 concentration and leads to simulated desorption curves that are in good agreement with the experimental outgassing data.

Publisher

American Physical Society

Publication Date

1-15-2005

Publication Title

Physical Review B

Department

Physics and Astronomy

Document Type

Article

DOI

https://dx.doi.org/10.1103/PhysRevB.71.045415

Language

English

Format

text

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