Bud-like silica nanowires with self-assembled long segmented stems: a novel nanostructure and its growth mechanism

A large quantity of bud-like silica nanowires with self-assembled long segmented stems were synthesized through thermal evaporation via using a piece of Si wafer and the mixture of Ga2O3 and carbon powder as source materials. The segmented stems were assembled from the bottom part of the bud-like silica nanowires with diameter of approximately 0.5 microm and length up to more than 20 microm. The bud-like silica nanowires could have one, two or three segmented stems. Some bud-like silica nanostrutures have a bowl-shaped cavity at their tips, others have a tail growing from their tips. The aligned silica nanowires were found extending from the thin silica shell coating the Ga ball, instead of nucleating and growing from the surface of the Ga ball directly. These interesting results could help us understand the diversity and versatility of the silica nanostructures which can be fabricated, and the knowledge of their growth mechanisms.