Accession Number : AD0681712

Title :   THE ROLE OF CONTAMINATION IN THE KINETICS OF OXIDE NUCLEATION OF TUNGSTEN AND MOLYBDENUM.

Descriptive Note : Technical rept.,

Corporate Author : ILLINOIS INST OF TECH CHICAGO DEPT OF METALLURGICAL ENGINEERING

Personal Author(s) : Hoover,Scott ; Rausch,Doyle ; Gordon,Paul

Report Date : JAN 1969

Pagination or Media Count : 39

Abstract : The field emission microscope was used to study the influence of foreign gases on the initial oxidation stages of molybdenum and tungsten. The technique was based on the known field enhancement effect exhibited by oxide microcrystals, allowing detection following their nucleation. Reactions were studied in pure oxygen and in oxygen mixtures at oxygen partial pressures of from 1.0 x 10 to the minus 7th power to 0.00001 torr. Substrate temperatures of molybdenum ranged from 380C to 755C, and for tungsten, from 670C to 980C. Effects of the presence of carbon monoxide were investigated with molybdenum, and of carbon monoxide, nitrogen, carbon dioxide and methane with tungsten. (Author)

Descriptors :   (*TUNGSTEN, OXIDATION), (*MOLYBDENUM, OXIDATION), REACTION KINETICS, CONTAMINATION, GASES, OXIDES, NUCLEATION, ELECTRON MICROSCOPY, CARBON MONOXIDE, CARBON DIOXIDE, NITROGEN, METHANE, TUNGSTEN COMPOUNDS, MOLYBDENUM COMPOUNDS

Subject Categories : Physical Chemistry
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE