Accession Number : AD0257035

Title :   THE MECHANISM OF OXIDE FORMATION IN THE INITIAL STAGES OF OXIDATION

Corporate Author : OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS

Personal Author(s) : RAUSCH,D.W. ; MOAZED,K.L. ; FONTANA,M.G.

Report Date : 14 APR 1961

Pagination or Media Count : 1

Abstract : Research was conducted on the mechanism of oxide formation by means of a field emission microscope with a tungsten emission tip. Changes in the emission were observed as a result of adsorption of residual gases on the emission tip at room temperature. An improvement was made in the technique for producing field emission tubes by the development of a refractory masking material for pyrex. The high-vacuum technique was refined by the addition of a second getter to the system and the use of a H-purge at elevated temperatures to decontaminate the isolation trap. As adsorption increased the following changes were observed in emission pattern: (1) a gradual decrease followed by an increase in total integrated emission intensity; (2) a gradual decrease followed by an increase in local emission intensity of the area around (111) regions bounded by (211) regions; (3) an initial increase followed by a decrease in the size of the lowintensity regions around (110) and (211); and (4) an initial decrease followed by an increase in the size of the low intensity regions around (100).

Descriptors :   *ELECTRON TUBES, *FIELD EMISSION, *OXIDATION, *OXIDES, ADSORPTION, CHEMICAL REACTIONS, CRYSTAL STRUCTURE, DIFFUSION, SURFACE PROPERTIES, TUNGSTEN

Distribution Statement : APPROVED FOR PUBLIC RELEASE