126 research outputs found
The effect of monomer evaporation on a simple model of submonolayer growth
We present a model for thin film growth by particle deposition that takes
into account the possible evaporation of the particles deposited on the
surface. Our model focuses on the formation of two-dimensional structures. We
find that the presence of evaporation can dramatically affect the growth
kinetics of the film, and can give rise to regimes characterized by different
``growth'' exponents and island size distributions. Our results are obtained by
extensive computer simulations as well as through a simple scaling approach and
the analysis of rate equations describing the system. We carefully discuss the
relationship of our model with previous studies by Venables and Stoyanov of the
same physical situation, and we show that our analysis is more general.Comment: 41 pages including figures, Revtex, to be published in Physical
Review
Numerical test of the damping time of layer-by-layer growth on stochastic models
We perform Monte Carlo simulations on stochastic models such as the
Wolf-Villain (WV) model and the Family model in a modified version to measure
mean separation between islands in submonolayer regime and damping time
of layer-by-layer growth oscillations on one dimension. The
stochastic models are modified, allowing diffusion within interval upon
deposited. It is found numerically that the mean separation and the damping
time depend on the diffusion interval , leading to that the damping time is
related to the mean separation as for the WV model
and for the Family model. The numerical results are in
excellent agreement with recent theoretical predictions.Comment: 4 pages, source LaTeX file and 5 PS figure
Growth of nanostructures by cluster deposition : a review
This paper presents a comprehensive analysis of simple models useful to
analyze the growth of nanostructures obtained by cluster deposition. After
detailing the potential interest of nanostructures, I extensively study the
first stages of growth (the submonolayer regime) by kinetic Monte-Carlo
simulations. These simulations are performed in a wide variety of experimental
situations : complete condensation, growth with reevaporation, nucleation on
defects, total or null cluster-cluster coalescence... The main scope of the
paper is to help experimentalists analyzing their data to deduce which of those
processes are important and to quantify them. A software including all these
simulation programs is available at no cost on request to the author. I
carefully discuss experiments of growth from cluster beams and show how the
mobility of the clusters on the surface can be measured : surprisingly high
values are found. An important issue for future technological applications of
cluster deposition is the relation between the size of the incident clusters
and the size of the islands obtained on the substrate. An approximate formula
which gives the ratio of the two sizes as a function of the melting temperature
of the material deposited is given. Finally, I study the atomic mechanisms
which can explain the diffusion of the clusters on a substrate and the result
of their mutual interaction (simple juxtaposition, partial or total
coalescence...)Comment: To be published Rev Mod Phys, Oct 99, RevTeX, 37 figure
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