Kinetics of H2 desorption from crystalline C60
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.
FitzGerald, S.A., R. Hannachi, D. Sethna, M. Rinkoski, K.K. Sieber, and D.S. Sholl. 2005. "Kinetics of H2 desorption from crystalline C60." Physical Review B 71(4): 045415.
American Physical Society
Physical Review B
Physics and Astronomy