Chemical oscillations are driven by a gradient of chemical potential and can only develop in systems where the substances are far from chemical equilibrium. We have discovered a new analogous type of oscillations in ternary electrolyte mixtures, which we call electromigration oscillations.They appear in liquid solutions of electrolytes and are associated with the electromigration movement of ions when conducting an electric current.
These electromigration oscillations are driven by the electric potential gradient, while the system can be close to chemical equilibrium. The unequivocal criterion for the instability of the electrolyte and its ability to oscillate is the existence of complex system eigenmobilities.We show how to calculate the system eigenmobilities by utilizing the linear theory of electromigration and how to identify the complex system eigenmobilities.
To experimentally prove these electromigration oscillations, we employ a commercially available instrument for capillary electrophoresis.