70,719 research outputs found
Random Deposition Model with a Constant Capture Length
We introduce a sequential model for the deposition and aggregation of
particles in the submonolayer regime. Once a particle has been randomly
deposited on the substrate, it sticks to the closest atom or island within a
distance \ell, otherwise it sticks to the deposition site. We study this model
both numerically and analytically in one dimension. A clear comprehension of
its statistical properties is provided, thanks to capture equations and to the
analysis of the island-island distance distribution.Comment: 14 pages, minor corrections. Accepted for publication in Progress of
Theoretical Physic
Fluctuations and scaling in models for particle aggregation
We consider two sequential models of deposition and aggregation for
particles. The first model (No Diffusion) simulates surface diffusion through a
deterministic capture area, while the second (Sequential Diffusion) allows the
atoms to diffuse up to \ell steps. Therefore the second model incorporates more
fluctuations than the first, but still less than usual (Full Diffusion) models
of deposition and diffusion on a crystal surface. We study the time dependence
of the average densities of atoms and islands and the island size distribution.
The Sequential Diffusion model displays a nontrivial steady-state regime where
the island density increases and the island size distribution obeys scaling,
much in the same way as the standard Full Diffusion model for epitaxial growth.
Our results also allow to gain insight into the role of different types of
fluctuations.Comment: 25 pages. Minor changes in the main text and in some figures.
Accepted for publication in Surface Scienc
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
Growth of three-dimensional structures by atomic deposition on surfaces containing defects : simulations and theory
We perform a comprehensive study of the formation of three dimensional
(pyramidal) structures in a large range of conditions, including the possible
evaporation of adatoms from the surface and the presence of surface defects. We
compare our computer simulations to theoretical calculations of the growth and
find good agreement between them. This work clarifies precedent studies of
three dimensional growth and predicts the island size distributions obtained in
the different regimes. Finally, we show how our analysis can be used to
interpret experimental data.Comment: 15 pages, Revtex. submitted to Surface Scienc
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