Numerical simulation of the mass transfer of magnetic species at electrodes exposed to small-scale gradients of the magnetic field

The mechanisms responsible for the spatially inhomogeneous thickness of metal layers obtained by electrochemical deposition in magnetic gradient fields at small scale are controversially discussed in the literature. The paper presents the results of numerical simulations which support the reasoning that local convection at the electrode, driven by the curl of the magnetic gradient force, is responsible for the effects observed. The deposition of paramagnetic and of diamagnetic ions is discussed, and the influence of electrically inert magnetic ions present in the electrolyte is enlighted.