We have studied the dereconstruction of Si(111)2 x 1 upon hydrogen adsorption by means of first-principles total energy and molecular dynamics calculations. We find that the (1 x 1) bulk-terminated surface structure becomes energetically favored over the (2 x 1), starting from a coverage theta approximately 0.3. This is consistent with LEED results showing that the dereconstruction is completed at theta approximately 0.5. A path for this conversion has been determined via direct simulation at theta = 0.5. This has a rather low energy barrier, approximately 0.10 - 0.15 eV/(surface atom), and should therefore occur with significant probability during hydrogenation of the surface.
Hydrogen-induced Dereconstruction of Si(111)-2x1 from First-Principles Molecular Dynamics
ANCILOTTO, FRANCESCO;
1992
Abstract
We have studied the dereconstruction of Si(111)2 x 1 upon hydrogen adsorption by means of first-principles total energy and molecular dynamics calculations. We find that the (1 x 1) bulk-terminated surface structure becomes energetically favored over the (2 x 1), starting from a coverage theta approximately 0.3. This is consistent with LEED results showing that the dereconstruction is completed at theta approximately 0.5. A path for this conversion has been determined via direct simulation at theta = 0.5. This has a rather low energy barrier, approximately 0.10 - 0.15 eV/(surface atom), and should therefore occur with significant probability during hydrogenation of the surface.Pubblicazioni consigliate
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