Abstract
One-dimensional polycrystalline Ta 2 O 5 nanostructures are synthesized by the annealing of the SiO 2 nanowires at 950°C in a reductive Ta vapor ambiance. The formation mechanism of Ta 2 O 5 nanostructures is discussed and illustrated in detail. The nucleation and grain growth of Ta 2 O 5 crystals were investigated during the formation of the SiO 2 /Ta 2 O 5 core-shelled structures. The diffusion-controlled growth is suggested to be the rate-determining step for the diffusion of the Ta atoms through the ash layer to react with O atoms and substitute Si atoms. © 2014 Hsu-Sheng Tsai et al.