Electrocrystallization of lead on copper single crystal planes: Some effects of superimposed “a.c.” on “d.c.”

Abstract The morphological features of lead electrodeposits, deposited from a highly purified acid lead perchlorate bath on copper single crystal planes have been investigated at various current density ranges to observe different growth features. In pure d.c. on the Cu(111) plane, a transition from triangular pyramids → hexagonal pyramids → twinned hexagonal pyramids → polycrystalline type of deposit was observed. On the Cu(100) plane, layers with occasional square pyramids observed at low current densities (d.c.) changed to a polycrystalline type of deposit at high d.c. current densities. Ridge type deposits on a Cu(110) plane observed at low d.c. current densities break up and produce a polycrystalline type of deposit at high d.c. current densities. “a.c.” of various magnitudes superimposed at a given value of d.c. current density, during the electrocrystallization of lead on copper single crystal planes brought about similar but more pronounced transitions in the morphology of lead electrodeposits. The mechanism of the mode of transformation in the type of deposits is discussed both in d.c. and in the presence of superimposed a.c.