AVS 46th International Symposium
    Surface Science Division Thursday Sessions
       Session SS1+EM+NS-ThA

Paper SS1+EM+NS-ThA6
Novel Temperature Dependence of the Morphology of Deposited Multilayer Ag/Ag(100) Films

Thursday, October 28, 1999, 3:40 pm, Room 606

Session: Metal/Metal Growth
Presenter: C.R. Stoldt, Iowa State University
Authors: C.R. Stoldt, Iowa State University
A.R. Layson, Iowa State University
C.J. Jenks, Iowa State University
M.C. Bartelt, Sandia National Laboratories
K. Caspersen, Iowa State University
J.W. Evans, Iowa State University
P.A. Thiel, Iowa State University
Correspondent: Click to Email
Metal(100) homoepitaxy provides a natural testing ground for recently developed ideas on kinetic roughening and "mound formation" due to step-edge barriers. Non-monotonic variation of roughness with deposition temperature (T) has been predicted,@footnote 1@ but not observed. Here, we report comprehensive VT-STM studies for growth of Ag/Ag(100) films between 130K and 300K which reveal this behavior. Roughness of 25ML Ag/Ag(100) films at first increases "classically" below 300K due to inhibited downward transport, but then decreases below 220K, achieving a low plateau value below 170K. Unlike Pt/Pt(111) and Rh/Rh(111) growth, non-monotonic behavior is not associated with a dramatic change in 2D island morphology, but rather with enhanced downward funneling from (the more prevalent) step edges at lower T. We also characterize the mound morphology, noting the steepness of the mound sides and small lateral dimension at lower T. A breakdown of kinematic scattering behavior of the intensities observed in our HRLEED studies of these films is attributed to this feature. Monte Carlo simulations of a realistic model for growth@footnote 1@ are consistent with and elucidate observed behavior. @FootnoteText@ @footnote 1@M.C. Bartelt and J.W. Evans, Surf. Sci. 423 (98) 189; Phys. Rev. Lett. 75 (95) 4250.