Diffusion in disordered fractalsDo Hoang Ngoc Anh1, K. H. Hoffmann1, S. Seeger1 and S. Tarafdar2
1 Institut für Physik, Technische Universität Chemnitz - D-09107 Chemnitz, Germany
2 Condensed Matter Physics Research Centre, Jadavpur University Kolkata 700032, India
received 5 October 2004; accepted in final form 11 February 2005
published online 9 March 2005
Diffusion in disordered media can be modelled by the anomalous diffusion in fractals. Up to now, usually regular fractals were used as models for such disordered systems. Here we study disordered fractals in an attempt to capture the random nature of the disordered material. In particular, we investigate the diffusion in fractals obtained by randomly mixing different Sierpinski carpet generators. We find that the random-walk exponent dw shows strong dependance on the mixture composition. For the mixed system it can be higher or lower than both the pure components. Further, dw may decrease on mixing, indicating faster diffusion in the disordered system.
61.43.Hv - Fractals; macroscopic aggregates (including diffusion-limited aggregates).
66.30.-h - Diffusion in solids.
© EDP Sciences 2005