TY - JOUR
T1 - Deposition, diffusion, and aggregation of atoms on surfaces
T2 - A model for nanostructure growth
AU - Jensen, Pablo
AU - Barabsi, Albert Lszl
AU - Larralde, Hernn
AU - Havlin, Shlomo
AU - Stanley, H. E.
PY - 1994
Y1 - 1994
N2 - We propose a model that describes the diffusion-controlled aggregation exhibited by particles as they are deposited on a surface. The model, which incorporates deposition, particle and cluster diffusion, and aggregation, is inspired by recent thin-film-deposition experiments. We find that as randomly deposited particles diffuse and aggregate they configure themselves into a wide variety of fractal structures characterized by a length scale L1. We introduce an exponent that tunes the way the diffusion coefficient changes with cluster size: if the values of are very large, only single particles can move, if they are smaller, all clusters can move. The introduction of cluster diffusion dramatically affects the dynamics of film growth. We compare our results with those of several recent experiments on two-dimensional nanostructures formed by diffusion-controlled aggregation on surfaces, and we propose several experimental tests of the model. We also investigate the spanning properties of this model and find another characteristic length scale L2 (L2L1) above which the system behaves as a bond percolation network of the fractal structures each of length scale L1. Below L2, the system shows similarities with diffusion-limited aggregation. We find that L1 scales as the ratio of the diffusion constant over the particle flux to the power 1/4, whereas L2 scales with another exponent close to 0.9.
AB - We propose a model that describes the diffusion-controlled aggregation exhibited by particles as they are deposited on a surface. The model, which incorporates deposition, particle and cluster diffusion, and aggregation, is inspired by recent thin-film-deposition experiments. We find that as randomly deposited particles diffuse and aggregate they configure themselves into a wide variety of fractal structures characterized by a length scale L1. We introduce an exponent that tunes the way the diffusion coefficient changes with cluster size: if the values of are very large, only single particles can move, if they are smaller, all clusters can move. The introduction of cluster diffusion dramatically affects the dynamics of film growth. We compare our results with those of several recent experiments on two-dimensional nanostructures formed by diffusion-controlled aggregation on surfaces, and we propose several experimental tests of the model. We also investigate the spanning properties of this model and find another characteristic length scale L2 (L2L1) above which the system behaves as a bond percolation network of the fractal structures each of length scale L1. Below L2, the system shows similarities with diffusion-limited aggregation. We find that L1 scales as the ratio of the diffusion constant over the particle flux to the power 1/4, whereas L2 scales with another exponent close to 0.9.
UR - http://www.scopus.com/inward/record.url?scp=33750859937&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.50.15316
DO - 10.1103/PhysRevB.50.15316
M3 - Article
AN - SCOPUS:33750859937
SN - 0163-1829
VL - 50
SP - 15316
EP - 15329
JO - Physical Review B
JF - Physical Review B
IS - 20
ER -