All Physics Faculty Publications

Title

Infrared Reflection-Absorption Spectroscopy of W(100)—H at 100 K

Document Type

Article

Journal/Book Title/Conference

Surface Science

Volume

210

Issue

3

Publication Date

3-3-1989

First Page

L215

Last Page

L222

DOI

10.1016/0039-6028(89)90595-5

Abstract

Using infrared reflection-absorption spectroscopy in conjunction with the broad-band technique of Fourier-transform interierometry, changes m the absorption spectrum of W(100) have been investigated as a function of H coverage at 100 K from 900 to 3900 cm−1. The changes measured upon initial adsorption indicate the removal of intrinsic-surface states 0.36 eV below the Fermi surface as well as the establishment of the unreconstructed-surface electronic absorption at ∼ 0.15 eV. The appearance of the 0.15 eV mode upon initial adsorption implies that the surface largely switches to an unreconstructed state at low coverages, consistent with H-atom immobility at low temperatures. For higher coverages [> 0.7 monolayer (ML) (2.0 ML  saturation)] the measured reflectivity changes show that free-carrier surface scattering dominates the coverage induced variations. It is seen that infrared measurements of these surface-scattering variations can lead to determination of the effective plasma frequency ohmsp of the metal.

Comments

Published by Elsevier in Surface Science. Publisher PDF is available through link above. Publisher requires a subscription to access article.

http://www.sciencedirect.com/science/article/pii/0039602889905955