Self-affine fractal vapour-deposited gold surfaces characterization by scanning tunnelling microscopy

The morphological evolution of the surfaces of gold deposits grown from the vapour on smooth glass under nonequilibrium conditions and incident angle near substrate normal is studied at the nanometer level by scanning tunnelling microscopy. For an average film thickness equal to or greater than 500...

Full description

Bibliographic Details
Authors: Salvarezza, Roberto Carlos, Vázquez, L., Herrasti, P., Ocón, P., Vara, J. M., Arvia, Alejandro Jorge
Format: article
Status:Published version
Publication Date:1992
Country:Argentina
Institution:Universidad Nacional de La Plata
Repository:SEDICI (UNLP)
Language:English
OAI Identifier:oai:sedici.unlp.edu.ar:10915/80010
Online Access:http://sedici.unlp.edu.ar/handle/10915/80010
Access Level:Open access
Keyword:Ciencias Exactas
Química
Fractales
scanning tunneling microscopy
Oro
Vapor de agua
self-affine fractals
Nanopartículas
Description
Summary:The morphological evolution of the surfaces of gold deposits grown from the vapour on smooth glass under nonequilibrium conditions and incident angle near substrate normal is studied at the nanometer level by scanning tunnelling microscopy. For an average film thickness equal to or greater than 500 nm, the interface thickness (ξ) reaches a steady state. Under these conditions, ξ depends on the scan length (L) as ξ ∝ L<sup>α</sup> with α = 0.35 ± 0.05 for L > d<sub>s</sub>, where d<sub>s</sub> is the columnar size, and α = 0.89 ± 0.05 for L < d<sub>s</sub>. These results indicate that the growing surface spontaneously reaches a steady state and it can be described as a self-affine fractal. The value of α for L > ds agrees with the prediction of ballistic deposition models without restructuring, whereas that for L < d<sub>s</sub> exceeds the prediction of ballistic models including restructuring.