Electrochemical Deposition of Cu under Superimposition of High Magnetic Fields

Cu was deposited from pure copper sulphate electrolytes with different concentrations under superimposition of vertical magnetic fields up to 13 T. Different orientations of the magnetic field to the electrode surface were investigated. If the magnetic field is oriented parallel to the electrode surface, a significant increase of the current density starts after exceeding a threshold. This depends on the concentration. The deposition behavior is mainly attributed to the forced convection generated by the Lorentz force. Other magnetically induced forces are negligible. In a magnetic field oriented perpendicular to the electrode surface the change of current density starts with a decrease or with oscillations followed by a strong increase at fields higher than 2 T. The behavior at low fields is determined by the Lorentz force generating a rotating flow at the edge of the electrode. At higher magnetic fields the paramagnetic force induces an additional driving force. As a result, at high magnetic fields the increase of current density is higher in the case of the perpendicular field to surface configuration than in the parallel field. The effect of microvortexes on the forced convection is discussed. © 2004 The Electrochemical Society. All rights reserved.