Growth of zinc hollow nanofibers and nanotubes by thermal evaporation–condensation–deposition route

Highly crystalline zinc hollow nanofibers are synthesised via evaporation–condensation–deposition process. Zinc granules are thermally evaporated within a quartz reactor flowing nitrogen equipped with a furnace. Nucleation of zinc vapours is produced at the exit of the furnace by fast expansion and cooling through a nozzle in a flowing nitrogen atmosphere. Fibers with a diameter 40–120 nm, depending on the operating furnace temperature Tvap, and length several microns, are deposited as fluffy bundles on the walls of the expansion nozzle. They exhibit a hollow morphology, as revealed by TEM analysis. Some new structures, we say nanoclubs, diameter 40–90 nm and typical length less than 300 nm, are also observed in correspondence of lower Tvap.