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Session Q06 - DCP: COMPLEXITY AT INTERFACES: X-RAY SCATTERING STUDIES AT INTERFACES
Mixed session, Friday morning, March 24, 8:00
Ballroom A3, San Jose Convention Center
Evolution of surfaces during growth was studied with x-ray reflectivity technique. Two types of measurements will be discussed; 1) measurements during sputter-growth on polished silicon substrates 70, 2900 (1993); R.P. Chiarello et al., submitted to Phys. Rev. B (1994) and 2) measurements during electrochemical oxidation and reduction cycles former case, the average height of surface moves with a constant deposition rate. The measurements were made for the films with thicknesses between 50 Å\ and 7000 Å\ and data analysis establishes an experimental evidence of the theoretically proposed dynamic scaling behavior of surface during growth. In addition to x-ray reflectivity measurements, ex situ scanning tunneling microscopy measurements were made to aid the data analysis and to calculate height-height distribution functions. Dependence of the surface characteristics on the argon partial pressure will be discussed. In the later case, the surface is roughened by oxidation-reduction cycles and the surface evolves while the average surface height does not change. A comparison between the electrochemical cyclic voltammetry measurements and x-ray measurements will be discussed. The values of scaling exponent, \beta , are found in both cases to be between 0.36 and 0.42. These values are considerably larger than 0.25 found in some of computational studies and smaller than 0.5 expected for random deposition. \vskip 8pt \par\noindent ^* Collaborators include R.P. Chiarello, H.K. Kim, and Z. Nagy; supported by DOE under contract W-31-109-Eng-38