Temperature-dependent effects during Ag deposition on Cu(110)

Abstract

The composition, structure, and morphology of ultrathin films grown by Ag deposition on Cu(110) were monitored as a function of temperature using low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), and medium-energy ion scattering (MEIS). Aligned backscattering measurements with 150 keV He ions indicate that the Ag resides on top of the Cu and there is no measurable surface compound formation. Analysis with LEED shows that initially the Ag is in registry with the substrate troughs. Further deposition results in a split-c(2×4) LEED pattern, which is characteristic of a distorted Ag(111) monolayer template. As verified by both AES and MEIS measurements, postmonolayer deposition of Ag on Cu(110) at 300K leads to a pronounced three-dimensional clustering. Ion blocking analysis of the Ag clusters shows that the crystallites have a distorted (110) growth orientation, implying that the Ag monolayer template undergoes a rearrangement. This growth orientation is supported by LEED results at 130 K, which indicate that Ag multilayers develop from a Ag–Cu interface where the Ag is captured in the troughs. Changes observed in the film structure and morphology are consistent with a film growth mechanism that is driven by overlayer response to the substrate corrugation.