Electron-Stimulated Desorption from Condense Branched Alkanes

Abstract

The electron-stimulated dissociation or desorption (ESD) of hydrocarbons is of relevance to the study of radiation-induced surface damage in organic solids and polymers, surface analysis, and radiation-induced surface chemistry. A number of such studies have been carried out on gas phase hydrocarbon systems [1]. Caution should be observed, however, in extrapolating gas phase results to the solid, since dissociation in the gas phase often occurs after a conversion of electronic excitation energy to vibrational energy which is inherently localized due to the isolation and finite extent of the molecule [2]. In an organic solid or polymer, however, the vibrational energy may be dissipated prior to dissociation, and the excitation energy must be localized in some other manner if dissociation is to occur. Condensed organic molecular solids offer the experimenter several other conveniences, including a wellcharacterized chemical structure, ease of desorption and the ability to systematically alter chemical structure as readily as in a gas phase study.