Accession Number : AD0429412

Title :   STUDY OF SURFACE PROPERTIES OF ATOMICALLY-CLEAN METALS AND SEMICONDUCTORS.

Descriptive Note : Progress rept. no. 4, 1 June-31 Dec 63,

Corporate Author : BARUS RESEARCH LAB OF PHYSICS BROWN UNIV PROVIDENCE R I

Personal Author(s) : Farnsworth,H. E. ; Campbell,B. D.

Report Date : DEC 1963

Pagination or Media Count : 14

Abstract : The (0001) Surfaces of CdS were examined by means of Low-Energy Electron Diffraction. Heating the CdS crystal in oxygen at 200C induces adsorption on the (0001) SPECULAR surface. The (0001) MATTE surface of a high purity CdS crystal was ex amined. The results for this crystal showed the presence of surface planes in agreement with the results for the same face of another CdS crystal whose purity was unknown. The (0001) MATTE surface of a high purity CdS crystal was prepared for examination without chemical etch and without exposure to temperatures higher than 400C. A weak diffraction pattern characteristic of diffraction from a (0001) plane and containing half integral as well as integral order beams in two major azimuths was obtained in agreement with the results for the (0001) SPECULAR surface. These results show that the chemical etch exposes the planes on the MATTE surface. Heating the crystal near 500C in a vacuum caused the appearance of planes as in the case of the chemical etch. Thus the plane on the MATTE surface is unstable under the conditions of chemical etch or heat treatment near 500C in a vacuum. (Author)

Descriptors :   (*CADMIUM COMPOUNDS, SURFACE PROPERTIES), (*SEMICONDUCTORS, ELECTRON DIFFRACTION), CLEANING, SULFIDES, SINGLE CRYSTALS, ETCHED CRYSTALS, ADSORPTION, OXYGEN, HEAT TREATMENT

Distribution Statement : APPROVED FOR PUBLIC RELEASE