ELECTRODEPOSITION - THE ROLE OF CONCENTRATION IN THE PHASE-DIAGRAM AND THE HECKER TRANSITION

We report an experimental study of the morphological phases of zinc el ectrodeposits. The microscopic morphology is based on two alternative growth mechanisms: tip splitting or dendritic, and is decoupled from t he macroscopic structure. The latter is characterized by the density o f branches and stability of the front. The key role in the microscopic selection is played by the initial concentration of zinc. The importa nce of ion availability is manifested again in the Hecker transition, where the departure from dense branching morphology coincides with the exhaustion of zinc from the original solution.