Homoepitaxial growth on nominally flat and stepped Cu(1 1 1) surfaces: island nucleation in fcc sites vs. hcp stacking fault sites

We have investigated island nucleation in homoepitaxial growth on nominally flat and stepped (vicinal) Cu(1 1 1) surfaces using scanning tunneling microscopy. While on nominally flat Cu(1 1 1), Cu islands nucleate in fcc sites, island nucleation occurs rather in hcp stacking fault sites on stepped Cu(1 1 1) surfaces. We propose that strain on surfaces introduced by steps plays a significant role for the preferred sites.