Electron- and Photon-Stimulated Desorption of Atomic Hydrogen From Radiation-Modified Alkali Halide Surfaces

Published

October 1, 2000

Author(s)

Lawrence T. Hudson, N H. Tolk, C Bao, P Norlander, D P. Russell, J. Xu

Abstract

The desorption yields of excited hydrogen atoms from the sufaces of KCI, KBr, NaCl, NaF and LiF have been measured as a function of incident photon and electron energy and flux, time of irradiation, dosing pressure of H₂ and sample temperature. As these surfaces are exposed to H₂ gas during electron or photon bombardment, the fluorescence from excited hydrogen atoms ejected from the surface is monitored. The desorption yields are found to be contingent upon surface damgage induced by the incident particle radiation leading to dissociate adsorption at surfacesites containing an excess of alkali metal. A desorption mechanism is presented in which incident electrons or photons induce a valence excitation to a neutral, antibonding state of the surface alkali hydride molecule/complex leading to the desorption of hydrogen atoms possessing several electron volts of kinetic energy.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

62

Issue

No. 15

Pub Type

Journals

Keywords

chemisorption, electronic desorption, hydrogen-surface interactions

Citation

Hudson, L. , Tolk, N. , Bao, C. , Norlander, P. , Russell, D. and Xu, J. (2000), Electron- and Photon-Stimulated Desorption of Atomic Hydrogen From Radiation-Modified Alkali Halide Surfaces, Physical Review B (Condensed Matter and Materials Physics) (Accessed April 24, 2024)