Accession Number : AD0651232

Title :   THE USE OF PRECISE SCHOTTKY DATA IN THE ANALYSIS OF THE METAL-VACCUM SURFACE BARRIER FOR THERMIONIC EMITTERS: I-RHENIUM,

Corporate Author : NOTRE DAME UNIV IND

Personal Author(s) : D'Haenens,I. J. ; Coomes,E. A

Report Date : 28 FEB 1967

Pagination or Media Count : 44

Abstract : The Schottky effect in thermionic emission carried to the second order is equivalent to an electron Fabry-Perot interferometer which may be used to investigate the physics of the emitter surface. This method has been used in a precise experimental determination of the Herring-Nichols surface-reflection coefficient mu from periodic deviations in the thermionic Schottky effect for rhenium. The value of mu=0.29 exp(i0.42) is in good agreement with a Sommerfeld box model in which the valence electrons of the atoms near the metallic surface are assumed to be free. It is suggested that this high density of Sommerfeld electrons at the emitter, resulting from radical modifications in the energy-level system as the surface is approached from deep in the crystal, associates with the dependence of work function on crystallographic direction and details of surface atomic structure. (Author)

Descriptors :   (*THERMIONIC EMISSION, *RHENIUM), INTERFEROMETERS, SURFACE PROPERTIES, METALS, VACUUM, CRYSTALS, ENERGY, ATOMIC STRUCTURE, ELECTRON DENSITY, CRYSTALLOGRAPHY, REFLECTION, VALENCE, ELECTRONS

Subject Categories : Electricity and Magnetism
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE