Accession Number : AD0660211

Title :   THE SURFACE PHYSICS OF SIMPLE AND COMPLEX ELECTRON EMITTERS.

Descriptive Note : Final technical rept., 1 Nov 54-31 Jul 67,

Corporate Author : NOTRE DAME UNIV IND

Personal Author(s) : Coomes,Edward A. ; Petrauskas,Alex A.

Report Date : 06 JUN 1967

Pagination or Media Count : 74

Abstract : The kinetics of adsorbed layers of KCl on W, Cl on W, Sr on W, O on W, and O on Mo have been investigated in the temperature range 300 degrees K to 1900 degrees K by means of field electron microscopy. The adsorption, desorption, and migration of Sr on W, Ba on W, and Sr on Mo were also examined. The variation of average work function of the surface with 'coverage', the Gibbs free energy for desorption, and the activation energy for migration around the (110) were measured. The polorizability of Sr was evaluated from four theories of adsorption. Only MacDonald and Barlow's theory gave results in agreement with other measurements and computations. For metal surfaces, theory and experiment in second order Schottky effect confirmed the mirror image nature of surface barrier up to distances of few lattice parameters, and has related the energy structure for the electrons in the surface layer to the interior structure of the emitter. (Author)

Descriptors :   (*CATHODES, SURFACE PROPERTIES), (*WORK FUNCTIONS, THERMIONIC EMISSION), WORK FUNCTIONS, TUNGSTEN, CHLORINE, STRONTIUM, CHLORIDES, OXYGEN, MOLYBDENUM, ELECTRON MICROSCOPY, HIGH TEMPERATURE, DYNAMICS, ADSORPTION, CRYSTAL GROWTH, FIELD EMISSION, FREE ENERGY, METALS, SOLID STATE PHYSICS, ELECTRONS

Subject Categories : Physical Chemistry
      Electrical and Electronic Equipment
      Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE