An Experimental Study of Electronic States at Metal-Dielectric Interfaces.
Abstract
During the past 24 months we have succeeded in developing two new infrared techniques which are ideally matched for the spectroscopic investigation of metal dielectric interfaces. The first technique is surface wave interferometry, which is described in Reports A, B and D. We show that edges, steps or dielectric discontinuities on metal surfaces produce two kinds of propagating waves: surface plasmons which are bound to the surface and bulk electromagnetic radiation. Since both waves are coherent interference effects can be readily observed. A two beam interferometer has been constructed on the metal surface to demonstrate the interference phenomena and also to provide an interferometric wavelength measurement of infrared surface waves. The geometry appears well suited for heterodyne spectroscopic study of surface states. The second technique is broad band surface electromagnetic wave spectroscopy, which is described in Reports C and E. The frequency range investigated so far is from 600 to 1800 per cm. A sharp absorption line near 1000 per cm in a molecular overlayer was used to compare the surface electromagnetic waves (SEW) and surface reflection spectroscopy techniques (SRS). The integrated optical density of the absorption line is an order of magnitude larger with SEW than with SRS, demonstrating conclusively that SEW is the more sensitive technique. We anticipate that the SEW broadband technique will be particularly useful for the spectroscopic investigation of the first steps of metal oxide growth. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 13, 1981
- Accession Number
- ADA097363
Entities
People
- A. J. Sievers
Organizations
- Cornell Laboratory of Atomic and Solid State Physics