Influence of external field on diffusion-limited aggregation

The influence of external electric field on diffusion-limited aggregation ( DLA) has been investigated by computer simulations. When the parameter lamb da increases from 0 to infinity, the morphology of aggregates changes from pure DLA to chain-like pattern gradually, where lambda stands for the relat ive strength of field-induced dipolar interaction to thermal energy. The st ructure transition is the transition between a prototype disorder structure and a relative order one in essence. The reason of the transition is the i nteraction controlling systems changes from thermal force to field-induced dipolar interactions with lambda rising. (C) 2000 Elsevier Science B.V. All rights reserved.