Ultrathin silver films on Ni(111)

作者：Meyer Axel^*; Flege J Ingo; Rettew Robert E; Senanayake Sanjaya D; Schmidt Thomas; Alamgir Faisal M; Falta Jens

来源：Physical Review B, 2010, 82(8): 085424.

DOI：10.1103/PhysRevB.82.085424

The growth and atomic structure of ultrathin silver films on Ni(111) was investigated by low-energy electron microscopy and diffraction (LEEM/LEED) as well as intensity-voltage [I(V)]-LEEM in the growth temperature range between 470 and 850 K. We find that silver grows in a Stranski-Krastanov mode with a two monolayer thin wetting layer which takes on a p(7X7) reconstruction at temperatures lower than 700 K and a (root 52 X root 52)R13.9 degrees reconstruction at higher temperatures. The occurrence of the two distinct reconstructions is shown to have profound implications for the growth characteristics of films exhibiting thicknesses of one and two monolayers. The nanoscale I(V) characteristics of the films were analyzed by means of multiple-scattering calculations based on dynamical LEED theory. Furthermore, the vertical interatomic spacing at the interface between the Ag film and the Ni substrate was determined to (2.8 perpendicular to 0.1) angstrom for all film thicknesses (<13 ML) while the uppermost silver layer relaxes by about (4 +/- 1)% toward the crystal.

• 出版日期2010-8-16