SURFACE-CHEMISTRY OF MONOLAYER METALLIC-FILMS ON RE(0001) AND MO(110)

The overlayer growth of Fe, Ni, and Cu on a Mo (110) surface and Fe and Cu on Re (0001) as well as adsorption of D2and CO on the prepared bimetallic surfaces have been studied in the sample temperature (Ts) range 115–1500 K, using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and thermal desorption spectroscopy (TDS). Fe, Ni, and Cu on Mo(110) and Fe and Cu on Re(0001) were found to grow layer by layer upon deposition at Ts= — 115 K whereas multilayer deposits, upon annealing to Ts> 330 K, nucleate into three-dimensional (3D) clusters. The 3D clusters of Fe and Cu are shown by LEED to be epitaxial with respect to the Mo(110) and Re (0001) substrates. Fe at submonolayer coverages is believed to form a strained pseudomorphic superlattice on Mo(liO) while similar coverages of Ni on Mo(110) and of Cu on Re(Q00 1) form a superstructure. The results of chemisorption of D2and CO on the prepared bimetallic surfaces Fe/Mo(110), Ni/Mo(110), and Cu/Re(G001) are presented and discussed. It is shown that these ultrathin metal films exhibit chemisorptive properties quite different from those of the bulk metal. © 1990, American Vacuum Society. All rights reserved.