Numéro |
J. Phys. Colloques
Volume 49, Numéro C6, Novembre 1988
35th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
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Page(s) | C6-3 - C6-6 | |
DOI | https://doi.org/10.1051/jphyscol:1988601 |
J. Phys. Colloques 49 (1988) C6-3-C6-6
DOI: 10.1051/jphyscol:1988601
THEORY OF FIELD ADSORPTION
H.J. KREUZERDepartment of physics, Dalhousie University, Halifax, N.S., B3H 3J5, Canada
Abstract
A first principles theory is formulated to calculate the dispersion (van der Waals) and polarization (induced dipole-dipole) interactions between a solid and an atom in a strong electric field. It is shown that these forces are not strong enough to bind rare gases on field ion tips. We then review a microscopic theory of field adsorption in which the electronic properties of the metal-adsorbate system are calculated within a tight binding cluster approach based on the ASEDMO method with local electric fields taken from self-consistent hellium calculations. Comparison with experiment for helium field adsorption on tungsten is excellent for activation energies, bonding distances and vibrational frequencies. Reference will also be made to the field-induced chemistry of NO on a platinum tip.