Growth and stability of Ag layers on Cu(110)

Combined surface science and high energy ion beam techniques have been used to characterize the composition, structure and thermal stability of Ag layers < 900A thick on Cu(110). A uniform Ag/Cu surface composite is formed for one monolayer coverage. Analysis of its growth with LEED shows that the Ag is initially confined to the (110) troughs and that further deposition results in a Ag(111) layer exhibiting c(2 x 4) symmetry. This surface science determination of Ag coverage is consistent with absolute coverages measured with Rutherford backscattering. Beyond one monolayer coverage, the deposition of Ag at 300K produces clustering (Stranski-Krastanov mechanism) in contrast to a poorly ordered but more uniform layering mode when deposited at 130K. Following nucleation for a deposition between one and two monolayers at 300K, Ag clusters approx.20 A thick grow laterally across the surface up to 5 or 6 monolayers deposition. Continuous films grown cold at thicknesses less than or equal to 115A are found to agglomerate above 500K exposing a tenacious Ag-Cu interface like that formed by one monolayer Ag deposition