Lateral instabilities of cubic autocatalytic reaction fronts in a constantelectric field

The region of instability for planar reaction fronts of cubic autocatalysis between ionic species under constant electric field has been determined ac curately. The ratio of diffusion coefficients at the onset of instability d elta(cr) is substantially varied by the component-dependent drift and direc tly proportional to the concentration of the autocatalyst behind the front beta(s) as delta(cr)=2.3002 beta(s). This opens the possibility to use elec tric field as a control parameter for reaction-front instabilities. The dis persion relation calculated from the linear stability analysis of the full system is in good agreement with the initial evolution of the Fourier modes associated with the slightly perturbed planar reaction front obtained by t he direct integration of the governing equations in two spatial dimensions. (C) 1999 American Institute of Physics. [S0021-9606(99)50148-7].