TEMPERATURE-PROGRAMMED DESORPTION OF MOLECULES FROM SOLID SURFACES: EFFECTS OF SURFACE SITE DISTRIBUTION AND LATERAL INTERACTIONS ON DESORPTION SPECTRA
Titel:
TEMPERATURE-PROGRAMMED DESORPTION OF MOLECULES FROM SOLID SURFACES: EFFECTS OF SURFACE SITE DISTRIBUTION AND LATERAL INTERACTIONS ON DESORPTION SPECTRA
Auteur:
Rivera, P. J. Hirtzel, C. S.
Verschenen in:
Chemical engineering communications
Paginering:
Jaargang 108 (1991) nr. 1 pagina's 333-346
Jaar:
1991
Inhoud:
The effects of surface site distribution are examined and compared using thermal desorption techniques (in particular, Monte Carlo simulation schemes to simulate temperature-programmed desorption). Specifically, the effects of lateral interactions among adatoms, surface heterogeneity, initial surface coverage, and desorption energy have been studied. Surface heterogeneity effects have been examined for desorption of a single species only. The effects of lateral interactions on the desorption spectra for different types of site distributions (in this case, a 10-site patch distribution, an alternating site distribution, random site distributions, and for a cluster of molecules on the center of the surface surrounded by molecules of a different type) are studied. Lateral interactions among adatoms provided a broad range of results depending on sign and magnitude of the interaction. It is also found that as the site energy increased, a molecule was held to the surface much more strongly, and observed desorption did not occur until temperature increased. Results are shown for a single layer distribution.
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