SCS colloquium: Growth of dendritic aggregates under magnetic field: a computational approach

ABSTRACT:

The application of a magnetic field during the electrodeposition of metals usually changes the shape and morphology of these deposits. For a normal magnetic field, among other effects, the radial symmetry turns into a spiral shape. And the application of the field in the plane of growth of the aggregates leads to a spectacular symmetry break where, for example, the dense circular morphology gets a rectangular envelope, and the sparse morphology becomes more linear and has less branches.

This work studies the quasi-2D electrodeposition of metals in a thin cell under the influence of magnetic fields. For that, two different computational approaches were used.

The first one deals with a modification of the diffusion-limited aggregation (DLA) algorithm in order to take into account the forces of the problem. Some interactions were introduced such as the Coulombian force; the Lorentz force due to a magnetic field applied normal to the plane of growth of the structures; and the Zeeman's energy for ferromagnetic particles and a field applied parallel to the plane of the growth; as well as the changes in the potentials around the aggregates produced by its shape. For the in-plane magnetic field, where hydrodynamic effects are not observed, the results show a good agreement with the experiments.