Stress-induced growth of aluminum nanowires with a range of cross-sections

The use of aluminum (Al) as a plasmonic building block has drawn increasing attention of late, due to its natural abundance, and extended tunability into the ultraviolet range. However, a controllable way to grow Al nanowires (NWs) in a bottom-up manner has not been reported. Here a facile, stress-induced growth process for Al nanowires, influenced by the concentration of applied hydrofluoric acid, is reported. Physical characterizations show the nanowires to be polycrystalline fcc Al with ultrasmooth surfaces, with many possible cross-section geometries, making them potential candidates for Al plasmonic investigations and applications. Dark-field optical analysis of a crescent-shaped Al NW demonstrates its plasmonic nature. These results may stimulate new interest in the fabrication of unconventional, nearly one dimensional Al nanostructures.