Adsorbate-induced changes in the broadband infrared reflectance of a metal: Oxygen on Cu(100)
Journal
Physical Review B
Journal Volume
49
Journal Issue
24
Pages
17273-17278
Date Issued
1994
Author(s)
KING-CHUEN LIN
Tobin, R.G.
Dumas, P.
Abstract
We have measured the adsorbate-induced change in the infrared reflectance of a Cu(100) surface upon adsorption of oxygen at room temperature, at four oxygen coverages, over the frequency range from 100 to 2000 cm-1. The observed frequency dependence provides an independent test of a model of conduction-electron scattering from disordered adsorbates that incorporates nonlocal electrodynamics. We find good agreement with theory for coverages below 0.25 ML. The value of the characteristic roll-off frequency ωpνF/c, however, which is predicted to be independent of the adsorbate, is different from that found for CO on the same crystal. At 0.35-ML coverage, the frequency dependence deviates strongly from the predicted form and the magnitude of the reflectance change decreases. It is possible that these deviations are related to an incipient ordering and reconstruction of the surface. © 1994 The American Physical Society.
Type
journal article