AFM study on morphology evolution of zinc electrodeposits

Nano-size growth of zinc electrodeposit is studied by using atomic force microscopy (AFM). The (0001)(eta) and {10(1) over bar 0}(eta) of hexagonal plate crystals are aligned parallel to the steel substrate with Sn++ as additive. An AFM cantilever is placed on these planes in order to focus the nano-size growth image on these planes. The (0001)(eta) consists of both 30 nm of granular crystals and alignments of these granular crystals, i.e. steps. These steps grow laterally as a result of the embedment of zinc ion clusters to the kinks of steps. The {10(1) over bar 0}(eta) and initial deposit also consist of these granular crystals. The initial zinc deposits are made up of the edges of hexagonal platelet crystals oriented ten to twenty degree from the substrate. The (0001)(eta) of hexagonal platelet crystals becomes parallel to the substrate as the deposit grows with Sn++ as additive. The {10(1) over bar 0)(eta), on the other hand, becomes parallel to the substrate without Sn++ as additive. These changes in the texture are caused by the locations of nucleation sites of the steps on the (0001)(eta).