Effect of ambient vacuum pressure on the corrosion properties of pure iron films formed by the ion beam deposition method

摘要

High purity iron films deposited on Si substrates by the low-energy, mass-separated ion beam deposition (IBD) method showed the highest corrosion resistance against NaCl solution than any other iron materials. The corrosion properties of the films depend on the ambient vacuum conditions during film formation. High pressure surroundings seem to bring gaseous compounds into the films, which make the surfaces unstable owing to a high density of defects in the films. Surface observations by transmission electron microscopy indicate the presence of a stable iron oxide layer on the IBD iron film which had formed under suitable vacuum conditions. The presence of fewer defects in IBD iron film seems to be a prerequisite of this protective oxide layer. (C) 1998 Elsevier Science S.A. All rights reserved. References: 6