Impact of surface phase transitions and structure on surface diffusion profiles of Pb and Bi over Cu(1 0 0)

• Published in: Surface science Vol. 600; no. 6; pp. 1265 - 1276
• Main Authors: Monchoux, J.P., Chatain, D., Wynblatt, P.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.03.2006; Amsterdam Elsevier Science; New York, NY
• Subjects: Auger electron spectroscopy; Bismuth; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Copper; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Lead; Physics; Surface diffusion; Lead; Bismuth; Auger electron spectroscopy; Surface diffusion; Copper; Diffusion profile; Phase transformations; Transition elements; AES; Surface structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2006.01.012

Surface diffusion of Pb and Bi over Cu(1 0 0) surfaces has been studied by scanning Auger microscopy techniques. The diffusion profiles of Pb and Bi have been found to be quite different. The results show that three major factors control the shapes of the surface diffusion profiles: (a) First order phase transitions, which lead to phase coexistence over specified coverage ranges, tend to produce abrupt changes in coverage versus distance profiles; (b) profiles can be affected by the existence of significant differences in the diffusion coefficients of the various phases present, and by the possibility (c) of important changes in diffusivity within a given phase, as a function of coverage, due to interactions between the diffusing atoms. In addition, it has been shown that the strong connection between diffusion profile shapes and the 2D phase diagram allows certain features of the 2D phase diagram to be determined from diffusion profiles.