Electrochemical characterization of Ni-Fe alloy codeposition under MHD control

The nickel-iron alloy electrodeposition is affected by a superimposed magnetic field. Some previous papers [Msellak et al., Magnetohydrodynamics, 39:487-493, 2003 and Msellak et al., J Magn Magn Mat, 281:295-304, 2004] have exhibited some dramatic changes in iron amount and morphology of these deposits. As it is usual for a magnetic field up to 1 T, no charge transfer effect can be expected, and the observed modifications can be explained by the magnetohydrodynamic convection that controls the iron species flux during the electrochemical reaction. By electrochemical impedance spectroscopy and physical investigations (scanning electron microscopy, X-ray diffraction, and inductively coupled plasma), the reduction process is analyzed, the characteristic parameters of the mechanism are determined, and the magnetic field effects can be quantified.