INVESTIGADORES
RAMIREZ PASTOR Antonio Jose
artículos
Título:
Influence of surface heterogeneities on the formation of diffusion-limited aggregates.
Autor/es:
M. NAZZARRO; F. NIETO; A. J. RAMIREZ-PASTOR
Revista:
SURFACE SCIENCE
Editorial:
Elsevier
Referencias:
Año: 2002 vol. 497 p. 275 - 284
ISSN:
0039-6028
Resumen:
In the present paper, we study the influence of surface energetic heterogeneities on the main features of fractal aggregates
generated through a diffusional mechanism. The diffusion-limited aggregation (DLA) model was introduced by
Witten and Sander (Phys. Rev. Lett. 47 (1981) 1400) and has stimulated growing interest in the study of a variety of
nucleation and growth processes since then. In the DLA model, growth begins with a seed particle in the center of a
two-dimensional lattice. Then, individual particles are launched uniformly from a launching circle, sufficiently big, and
they perform activated random walk until they stick to the growing cluster. The DLA clusters formed in this way are
fractal objects with a well determined fractal dimension df ¼ 1:72 0:02. In order to include surface heterogeneities, we
have used a square lattice with two kinds of sites which are assembled in such a way that the resulting structures have
patchwise topography. Lattices formed by collections of orderly localized patches of different sizes are generated. DLA
clusters are clearly affected in their morphology due to the presence of the surface heterogeneities which is analyzed and
explained in terms of the different energetic topographies.df ¼ 1:72 0:02. In order to include surface heterogeneities, we
have used a square lattice with two kinds of sites which are assembled in such a way that the resulting structures have
patchwise topography. Lattices formed by collections of orderly localized patches of different sizes are generated. DLA
clusters are clearly affected in their morphology due to the presence of the surface heterogeneities which is analyzed and
explained in terms of the different energetic topographies.