AVS 46th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS-WeP

Paper SS-WeP12
Formation of a Smooth and Pure Chromium Oxide Film on Stainless Steel Surface by Oxidation

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: B. Cho, Pohang University of Science and Technology, South Korea
Authors: B. Cho, Pohang University of Science and Technology, South Korea
S. Chung, Pohang University of Science and Technology, South Korea
Correspondent: Click to Email
Oxidation of stainless-steel for annealing temperature of 450 °C in oxygen partial pressures of 10@super -9@ to 10@super -4@ Torr was tested to form a smooth and pure chromium oxide film on the surface. Atomic force microscopy and scanning tunneling microscopy images show that oxidations in low oxygen pressures (10@super -9@ and 10@super -8@ Torr) favor the formation of not only macroscopically but also atomically smooth oxide films, which is almost total chromium oxide, as characterized by X-ray photoelectron spectroscopy. But oxidations in high oxygen pressures (10@super -6@ and 10@super -4@ Torr) prefer the development of very rough oxide films with distinct grains and significant proportion of iron. Considering that rough surfaces usually provide more adsorption sites for impinging molecules than smooth surfaces and pure chromium oxide films block hydrogen diffusion from bulk material more efficiently than inhomogeneous iron-rich oxide films, oxidation with low oxygen pressure may be a promising technique for the fabrication of a stainless steel vacuum chamber with enhanced outgassing characteristics.