Pattern Formation in Electrical Exploding of Thin Metal Films

We present the experimental results of the nanometer Zn films electrical explosion in the air. The film destruction is accompanied with the stratification; the strata are formed in the transverse direction to the applied electric field. The initial strata growth can be explained by the electro-thermal instability development. The strata propagation velocity reaches 50 km/s and depends on the current. The pattern is formed during ~60 ns and each stratum's voltage settles at the constant level limited by arc discharges. We found that strata fractal dimension D=1.55±0.02 for all experiments, which means that the patterns are determined by a certain universal mechanism.