Holographic microphotography study of periodic electrodissolution of iron in a magnetic field

Abstract

The periodic potentiostatic current oscillations of the stationary iron electrode during the transition from the active to the passive state are studied in 0.5 mol dm −3 H 2SO 4 solution in the presence of magnetic fields by the holographic microphotographic technique. This periodic behaviour appears to be quite sensitive to the strength of the magnetic field. At a high intensity of the magnetic field (100 mT), the oscillations disappear. The existence of the magnetic field enhances the mass transport rate by the magnetohydrodynamic (MHD) flow which changes the current oscillatory behaviour. The opposite effect to that of the magnetic field caused by the addition of glycerol in the solution provides further support to the influence of magnetic fields on the current oscillations.