AVS 46th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS3+EM-WeM

Paper SS3+EM-WeM9
Atomic and Electronic Structure of Ag/Ni(110) and Ni/Ag(100)

Wednesday, October 27, 1999, 11:00 am, Room 604

Session: Surface Electronic Structure
Presenter: D.A. Hite, Louisiana State University
Authors: P.T. Sprunger, Louisiana State University
D.A. Hite, Louisiana State University
Correspondent: Click to Email
The atomic and electronic structure of Ag on Ni(110) and Ni on Ag(100) has been studied by synchrotron-based angle-resolved photoemission spectroscopy (ARUPS), low energy electron diffraction and scanning tunneling microscopy. These systems are of interest due their high bulk lattice mismatch and immiscibility. STM results of the Ag/Ni(110) system have revealed a novel pseudomorphic, surface-confined alloy phase at a coverage of ~0.5 ML. ARUPS results of this phase show a bulk-like, 3-D Ag electronic structure due to strong hybridization with the Ni bands. However, at a coverage of 1 ML, the Ag "de-alloys" and structurally forms a strained ~ Ag(111) overlayer. The electronic structure of this phase is radically different, namely, the laterally localized Ag d-bands show only k-parallel dispersion, that is, 2-D structure. In contrast, ARUPS results of Ni monolayer deposition on Ag(100) reveals no alloy formation below 150 K. However, at deposition temperatures above 400 K, Ni segregates subsurface, resulting in a Ag surface termination. The underlying Ni adopts Ag lattice parameters. ARUPS data from this latter phase reveals 3-D, bulk-like electronic structure due to strong mixing of states. The results will be compared and contrasted with theoretical band-structure calculations. This research is funded by DOE through contract DE-FG-02-98ER45712.