Complex dynamics during metal dissolution: from intrinsic to faceted anomalous scaling.

The kinetic roughening of dissolving polycrystalline pure iron has been studied. A depth analysis of surface images has shown two consecutive growth regimes characterized by different scaling anomalous properties: an initial intrinsic anomalous scaling evolving in the thick film limit towards the theoretically conjectured faceted anomalous scaling. This represents the first experimental evidence of such scaling as well as of such transition. The dynamics presented here may account for the striped surface pattern observed during the evolution of metals or alloys in a large number of processes.