Yr. Tzeng et al., BEHAVIOR OF NI ATOMS ON THE CU(111) SURFACE - A STUDY BY HIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTROSCOPY, Physical review. B, Condensed matter, 48(8), 1993, pp. 5549-5554
The temperature-dependent behavior of vapor-deposited Ni atoms on the
Cu(111) surface has been studied by HREELS. Submonolayer coverage of N
i atoms are vapor-deposited on this surface in ultrahigh vacuum in the
temperature range of 140-600 K. CO is used to monitor the structure o
f the Ni-covered Cu(111) surface at various Ni-deposition temperatures
. For submonolayer Ni deposition at T=140 K, no significant diffusion
of Ni atoms is observed. Above 150 K, Ni atoms begin to diffuse on the
Cu(111) surface to form two-dimensional islands. At T > 260 K, atomic
exchange with the substrate atoms occurs and a mixed Ni-Cu monolayer
is formed. Above 600 K, Cu atoms segregate to the surface and Ni atoms
disappear completely from the top surface layer.