ELECTRON-ENERGY-LOSS SPECTROSCOPY (EELS) OF THERMALLY EVAPORATED CU DEPOSITED ON MGO(100) MO(100)/

Thermally evaporated Cu atoms are deposited in situ in submonolayer qu antities on a MgO(100) film. At low substrate temperatures (30 K < T < 180 K), the measured electron energy loss spectra display characteris tic losses within the MgO band gap. A preliminary analysis of the spec troscopic fingerprints in terms of atomic-like transitions is presente d. From a drastic change in these spectra upon deposition at substrate temperatures between 180 K and 220 K, we infer Cu island formation an d deduce a diffusion barrier height of 0.50(5) eV. (C) 1998 Elsevier S cience B.V. All rights reserved.