INVESTIGADORES
SOBA Alejandro
artículos
Título:
Nature of inclined growth in thin-layer electrodeposition under uniform magnetic fields
Autor/es:
ALEJANDRO SOBA; GRACIELA GONZALEZ; LUCAS CALIVAR; GUILLERMO MARSHALL
Revista:
PHYSICAL REVIEW E
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2012 vol. 86 p. 1 - 7
ISSN:
1539-3755
Resumen:
Electrochemical deposition (ECD) in thin cells in a vertical position relative to gravity, subject to an external
uniform magnetic field, yields a growth pattern formation with dense branched morphology with branches tilted
in the direction of the magnetic force. We study the nature of the inclined growth through experiments and
theory. Experiments in ECD, in the absence of magnetic forces, reveal that a branch grows by allowing fluid to
penetrate its tip and to be ejected from the sides through a pair of symmetric vortices attached to the tip. The
upper vortices zone defines an arch separating an inner zone ion depleted and an outer zone in a funnel-like
form with a concentrated solution through which metal ions are carried into the tip. When a magnetic field is
turned on, vortex symmetry is broken, one vortex becoming weaker than the other, inducing an inclination of
the funnel. Consequently, particles entering the funnel give rise to branch growth tilted in the same direction.
Theory predicts, in the absence of a magnetic force, funnel symmetry induced through symmetric vortices driven
by electric and gravitational forces; when the magnetic force is on, it is composed with the pair of clockwise
and counterclockwise vortices, reducing or amplifying one or the other. In turn, funnel tilting modifies particle
trajectories, thus, growth orientation.