HIGH-RESOLUTION LEED PROFILE ANALYSIS AND DIFFUSION BARRIER ESTIMATION FOR SUBMONOLAYER HOMOEPITAXY OF AG AG(100)/

We present a high-resolution low-energy electron diffraction study of two-dimensional island distributions formed by depositing 0.3 ML of Ag on Ag(100). The substrate temperature ranged between 170 and 295 K. F rom the ring structure or ''splitting'' of the diffraction profiles, w e determine the behavior of the spatial correlation length characteriz ing the island distribution. The precise relationship between this cor relation length and the mean island separation is also determined via an analysis of kinematic diffraction from island distributions in a re alistic model of nucleation and growth. Resulting estimates of this se paration are consistent with those based on results from a previous sc anning tunneling microscopy study at 295 K. From the Arrhenius behavio r of the correlation length, we estimate a terrace diffusion barrier f or Ag on AE(100) of 0.40 +/- 0.04 eV, with a vibrational prefactor of about 3 X 10(13) s(-1).