A crystallographic orientation transition and early stage growth characteristics of thin Bi films on HOPG

We report on the growth of ultra-thin bismuth films on the basal plane of highly ordered pyrolitic graphite (HOPG) substrates. Scanning electron microscopy and atomic force microscopy have been used to characterize the morphology, and the crystallographic orientation was obtained using electron back scatter diffraction. Low coverage films are comprised of islands with a striped surface morphology, and show the orientation relationship { 0 1 1 ¯ 2 } Bi ∥ { 0 0 0 1 } HOPG with preferred in-plane orientations 〈 1 1 2 ¯ 0 〉 Bi ∥ 〈 1 0 1 ¯ 0 〉 HOPG . With increasing film thickness, we identify an unusual orientation transformation to the commonly found Bi{0 0 0 1} (trigonal) orientation.