Electric field induced lateral instability in a simple autocatalytic front

The effect of ionic drift caused by small constant electric field on autoca talytic reaction fronts of ionic species is studied both theoretically and numerically. Besides varying the velocity of propagation, the electric fiel d parallel to the direction of propagation may induce lateral instability i n planar fronts resulting in the emergence of cellular structures. The diff erence in the diffusivities at the onset of instability are lowered when th e electric field tends to separate the species spatially. The predictions o f the linear stability analysis based on a thin-front approximation are con firmed by the numerical integration of the full two-dimensional system. (C) 1999 American Institute of Physics. [S0021-9606(99)51625-5].