Synthesis and growth mechanism of zinc oxide nanostructures in arc discharge

Nanodimensional tubes, needles, and tetrapods of zinc oxide (ZnO) with lengths up to ∼1 μm and diameters up to several hundred nanometers have been synthesized for the first time using an arc discharge method. A distinctive feature of the proposed method is the broad variety of evaporated and deposited products. The possible mechanism of evaporation, nucleation, and growth is suggested. Initially, the primary sheets are growing; these sheets turn into rolls and tubes, which eventually transform into needles. Tetrapods crystallize and grow in the gas phase and form a white snowlike deposit.