Epitaxy of CuI on Cu(111)

Thin epitaxial films of CuI have been grown on clean Cu(111) surfaces by chemical reaction with iodine vapor. A lattice match is obtained because the iodine (111) planes of CuI have the same symmetry and approximately the same spacing as the (√3×√3)R30° iodine adsorbate layer which forms initially on exposure of clean Cu(111) to iodine vapor. This suggests that pairs of materials favorable for heteroepitaxy can consequently be identified by searching for agreement between submonolayer adsorbate structures and atom planes in solids.