A224 Surface Science 189/190 (1987) 557-562 North-Holland, A m s t e r d a m CALCULATIONS WITHIN
THE
OF THE TRAJECTORY
557
STICKING
COEFFICIENT
OF Ne ON
Cu(100)
APPROXIMATION
M. PERSSON Institute for Theoretical Physics, Chalmers Unit, ersitv of Technology, S-412 96 GOteborg. Sweden and J. H A R R I S lnstitut ]'fir FestkOrperforschung der KFA Jiilich, D-5170 JiJlich, bed. Rep. of Germany Received 12 April 198% accepted for publication 16 April 1987 The results of trajectory approximation calculations of the sticking coefficient of a Ne atom (and a D~ molecule) on a low-temperature Cu(lO0) crystal due to excitation of p h o n o n s are summarized. The dependence of the sticking coefficient and the probability of elastic scattering on the incident energy and angle and on the details of the coupling to the phonons is discussed. -Fhe new feature of this calculation is that it uses realistic three-dimensional trajectories and p h o n o n s of a discrete lattice.
OF Sn ON Si(100) SURFACE PROPERTIES I. A N D R I A M A N A N T E N A S O A ,
J.P. LACHARME
and C.A. SI~BENNE
Laboratoire de Physique des Solides, associ~ au C N R S No. 154, Universit~ Pierre et Marie Curie. 75252 Paris Cedex 05, France Received 31 March 1987; accepted for publication 6 May 1987 The initial steps of ultrahigh-vacuum deposition of Sn on clean Si(100) surfaces have been studied using low-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and photoemission yield spectroscopy (PYS). While the initial 2 × 1 reconstruction reduces to 1 × 1 between 0.5 and 1 monolayer (1 ML = 6.8 × l0 TM atoms per cmz along the (100) face of Si), Sn forms a uniform overlayer up to 2 ML and then grows as metallic islands. The ionization energy and work function decrease in parallel, and the largest part of the decrease occurs upon 0.25 ML of Sn. New features start to grow in the band of filled surface states beyond 0.25 M L of Sn. The results are compared to Sn adsorption on cleaved 2 × 1 reconstructed Si(ll 1).