The relationship between the growth shape of three-dimensional Pb islands on Cu(100) and the domain orientation of the underlying c(5√2 x √2)R45 structure

We use low-energy electron microscopy to identify a correlation between the growth shape of three-dimensional Pb islands on Cu(100) and the domain structure of the underlying Pb overlayer. Deposition of 0.6 monolayer Pb on Cu(100) produces a compressed c(2 x 2) overlayer, designated c(5 root2 x root2)R45, with periodic rows of anti-phase boundaries. We find that heating the surface to temperatures above 100 degreesC coarsens the orientational domains of this structure to sizes that are easily resolved in the low-energy electron microscope. Three-dimensional Pb islands, grown on the coarsened domains, are found to be asymmetric with orientations that correlate with the domain structure. Once nucleated with a preferred growth orientation, islands continue to grow with the same preferred orientation, even across domain boundaries. (C) 2000 Elsevier Science B.V. All rights reserved.