Influence of the catalyst volume on the morphological transition of SiOx nanostructures

Two different-sized SiOx nanowires and microtubes were grown from the surface of Si substrate, according to the distribution of Sn nanoparticles on the Si substrate. The numerous Sn nanoparticles obtained from pre-deposited SnO2 films on the tube play two roles simultaneously: the first is to act as a type of catalyst for promoting a rapid nucleation and growth, and the second is to decrease the melting point of the Si substrate. In order to maintain the phase equilibrium, changes at a morphological (nanowire, microtube, and split loops) and elemental compositional (aggregation and dispersion) level are involved in the Sn volume.