Experiments on Electrodeposit Patterns
Experiments in electrochemical deposit patterns with a CuSO4 or ZnSO4 solution in a thin cell with parallel electrodes are presented. For CuSO4 the electrodes are copper strips and for ZnSO4 the electrodes are either copper or zinc strips. The control parameters are the solution concentration (C), the dc voltage across the electrodes (V), and the thickness of the cell (d). In our experiments, d varies from 0.1 to 0.7 mm, C varies from 0.025 to 1 M, and V reaches up to 30 V. For each run the voltage was held constant while the variation of the current with time and growth rate of the pattern was recorded. In addition to the well known patterns such as dendrites and strings, we find new patterns. Also, phase transitions may occur in which the filament thickness changes abruptly at some line parallel to the electrodes and this line is usually not at half of the separation between the two electrodes, in contrast to the case of radial cells. The forms of patterns depend very sensitively on the cell thickness. We conclude that processes underlying this type of pattern formation experiments cannot be considered strictly two dimensional.
KeywordsTransition Line High Versus Copper Electrode Zinc Sulphate Cell Thickness
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