Accession Number : AD0715283

Title :   Interaction of Molecules with Solid Surfaces.

Descriptive Note : Final rept. 1 Oct 65-30 Sep 70,

Corporate Author : VERMONT UNIV BURLINGTON DEPT OF PHYSICS

Personal Author(s) : Crowell,Albert D.

Report Date : OCT 1970

Pagination or Media Count : 10

Abstract : The report describes research concerned primarily with the effects of chemisorption of CO on molybdenum surfaces. Samples of molybdenum were outgassed in ultra high vacua and exposed to the gas under study. In the case of CO, the molecules were tagged with 14C to permit the determination of the number of molecules on the surface. Binding energies for these molecules were found by combining radiotracer measurements with thermal desorption studies. A new technique of analyzing the photoelectric yields which shows promise of leading to greater understanding of electronic changes produced at metal surfaces by gas adsorption has been developed. The method is based experimentally upon the identification of electron emitted from the surface by vectorial effects and theoretically upon a model which includes an explicit excitation mechanism. Studies of the changes in the electrical conductivity of evaporated metal films due to gas adsorption have been conducted both by DC and AC techniques. A new computer technique has made possible the characterization of the AC properties of thin films in terms of a simple equivalent circuit with frequency independent parameters. (Author)

Descriptors :   (*CARBON MONOXIDE, *ADSORPTION), (*MOLYBDENUM, ADSORPTION), (*PHOTOELECTRIC EFFECT, SURFACES), TRACER STUDIES, FILMS, ELECTRICAL CONDUCTIVITY, VAPOR PLATING

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE