Accession Number:

AD0684562

Title:

STUDIES OF PHYSICAL AND CHEMICAL PROPERTIES OF SOLID SURFACES.

Descriptive Note:

Final rept.,

Corporate Author:

SYSTEMS RESEARCH LABS INC DAYTON OHIO

Personal Author(s):

Report Date:

1968-11-01

Pagination or Media Count:

98.0

Abstract:

Detailed calculations of reflection coefficient of the Nb110 surface are presented. The basis of the calculations is the McRae multiple scattering theory for low energy electron diffraction. Enough detail is presented to point out how to apply the theory for the s-wave scattering case for many metals. In essence, the method is to determine the reduced effective field by use of matrix methods. The dynamical structure factor is then found, followed by the reflection coefficient. Results of ultra-thin film studies are presented. Aspects of the tinNb110 system have been studied by low energy electron diffraction techniques. The type of surface structure one obtains was found to depend upon the rate of evaporation. A diffuse phase results from rapid evaporation 10 layerssec. Sn110 or a 3x1 structure can be obtained in low rate 2 layerssec cases in which substrate is not heated during evaporation. Both cases produce Nb3Sn110 structure by heating to high temperature the exact temperature depending upon the rate at which the film was formed. Characteristic energy loss measurements confirm the presence of tin in low rate case and when LEED pattern and specular intensity curve did not indicate presence of tin. This last point is briefly discussed. A low energy electron spectroscopy LEES apparatus is briefly described, the design of which is based upon that constructed by Propst et al. The details of operation are presented. Author

Subject Categories:

  • Physical Chemistry
  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE