Local-field effect in optical reflectance from adsorbed overlayers

Publisher Website
Google Scholar
Abstract
The importance of the local-field effect in differential reflectance spectroscopy is demonstrated by means of numerical calculations done for the system of argon adsorbed on an aluminum substrate at two coverages. The calculations show that peaks in differential reflectance are not simply proportional to the adsorbate coverage, and their locations (in energy) change as the coverage is changed. Two models are considered for the substrate dielectric response—a local dielectric constant, and a nonlocal response based on the semiclassical infinite-barrier model. The local-field effect is shown to exist independent of the model considered for the substrate dielectric response. Connection is made with the available experimental data wherever appropriate.