Accession Number:

ADA232696

Title:

Oxidation Studies of Fluorine Containing Diamond Films

Descriptive Note:

Technical rept.

Corporate Author:

NORTHWESTERN UNIV EVANSTON IL DEPT OF MATERIALS SCIENCE AND ENGINEERING

Report Date:

1991-02-26

Pagination or Media Count:

18.0

Abstract:

The thermogravimetric method is used to study the oxidation properties of plasma grown diamond films both with and without fluorine. The oxidation experiments are carried out over a temperature range of 600 C - 800 C and in pure oxygen at one atmospheric pressure. Our experiments show diamond films with fluorine are more resistant by as much as a factor of 4 at 700 C to oxidation. The activation energy for oxidation, on the other hand, is at least a factor of 2.3 lower for diamond films with fluorine. These results lead us to postulate that oxidation mechanisms for diamond films are quite different depending on whether there is fluorine or not. For diamond films without fluorine the oxidation seems to proceed as a rate limited reaction, while for films with fluorine the oxidation seems to be a diffusion limited reaction. There is also a weak dependence of oxidation rates on film density, crystal texture, and the phase composition of the diamond film.

Subject Categories:

  • Inorganic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE