Accession Number : AD0663427

Title :   ADSORPTION ON SINGLE CRYSTAL PLANES.

Descriptive Note : Final rept.,

Corporate Author : NATIONAL BUREAU OF STANDARDS WASHINGTON D C

Personal Author(s) : Young,Russell D. ; Clark,Howard E.

Report Date : SEP 1967

Pagination or Media Count : 37

Abstract : A working instrument has been developed and tested for measuring work functions of perfect single crystal planes. The longstanding high work function value (6.0 eV) for emission from the (110) plane of tungsten was investigated using the new FN plus energy distribution technique. The new results yield still higher work function values than previously reported (8.8 eV). A theory has been developed to include the influence of surface patch fields from adjacent single-crystal planes on field emission from single-crystal planes. This theory led to a new method for interpreting field emission data which removes the influence of patch fields. It has been shown that the high work function values can be explained, at least in part, by assuming that electrons are emitted in pairs. This was studied experimentally and it was concluded that electrons are not in fact emitted in pairs. Preliminary experiments employing strontium adsorbed on tungsten demonstrate that the arrival of single strontium atoms at the surface can be detected. Thus the theory of Duke and Alferieff can be checked experimentally. (Author)

Descriptors :   (*TUNGSTEN, SINGLE CRYSTALS), (*SINGLE CRYSTALS, WORK FUNCTIONS), FIELD EMISSION, STRONTIUM, ADSORPTION, PREDICTIONS, ELECTRONS, EMISSIVITY, TEST EQUIPMENT

Subject Categories : Physical Chemistry
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE