One-dimensional surface reconstruction as an atomic-scale template for the growth of periodically striped Ag films

The role of the In/Si(111)-(4 x 1)-In surface as an atomic-scale geometrical template for the growth of Ag thin films is clarified by scanning tunneling microscopy and low energy electron diffraction. Low-temperature grown Ag films are found to have stripe structures with a transverse periodicity equal to that of indium chains of the In/Si(111)-(4 x 1)-In. The stripes exhibit a structural transformation at the thickness of 6 monolayers (ML); this relaxation allows the stripes to persist up to a thickness as large as 30 ML (approximately = 7 nm) while maintaining their mean periodicity. We attribute this stability to a coincidental matching of the periodicity and the corrugation amplitude between the Ag film and the substrate, which is realized by periodic insertion of stacking faults into a Ag fcc crystal.