Oscillatory Lorentz-force-driven flows during potentiostatic current oscillations in magnetic fields

The velocity and refractive index fields during potentiostatic current oscillations of iron electrode in H2SO4 with applied magnetic fields were measured by a combination of particle image velocimetry and interferometry. Depending on the magnetic field orientation differently oriented swirling flows around the electrode were observed in the activation phase. The resulting secondary flows crucially affect the concentration boundary layer thickness at the iron electrode, which finally strongly influences the duration of the passivation phase.