Studies of the Ag-Ge(100) interface

The growth mechanism, chemical interaction, crystallographic relationships, and electronic properties of Ag deposited at room temperature on Ge(100)-(2×1) were studied. Nucleation of deposited Ag at about ⅓ monolayer coverage to form flat and metallic Ag(110) islands was observed with high-energy electron diffraction and photoemission from the valence bands. The growth of Ag at higher coverages was determined to be three dimensional. The $3d$ core levels of surface atoms of Ge(100)-(2×1) did not shift relative to the bulk with Ag coverage of a few monolayers, indicating a very weak interaction between Ag and Ge and negligible intermixing. Annealing experiments showed that the deposited Ag became highly clustered at elevated temperatures and did not wet the Ge(100)-(2×1) surface. We will compare the present results with those for Ag deposited on Ge(111).