Accession Number : AD0277904

Title :   OXIDE NUCLEATION AND GROWTH

Corporate Author : CORNELL UNIV ITHACA NY

Personal Author(s) : ORR, WILLIAM HAROLD

Report Date : 01 APR 1962

Pagination or Media Count : 1

Abstract : Although the interaction of O with a clean metal surface is usually interpreted in terms of homogeneous chemisorption, careful kinetic measurements of the very initial takeup of O by a clean Mg surface indicate that the first stage of the process is dominated by nucleation and growth of the oxide phase at certain preferred sites on the metal surface. This interpretation is supported by the observed structure of the oxide film. The Wagener flow method was used to study the kinetics of oxide film formation at very low oxygen pressures from 77 to 304 K. The structures of the metal surface and oxide film were studied by electron microscopy and electron diffraction. During the first stage of oxidation the sticking probability S increased with takeup of oxygen. Once the oxide islands had grown together the sticking probability decreased as the oxide film thickened. During both stages of the oxidation process, the sticking probability was independent of the oxygen pressure. (Author)

Descriptors :   ADSORPTION, GROWTH(PHYSIOLOGY), OXIDATION, SURFACE PROPERTIES, SURFACES.

Distribution Statement : APPROVED FOR PUBLIC RELEASE