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Large-scale Synthesis of β -SiC Nanochains and Their Raman/Photoluminescence Properties

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ABSTRACT

Although the SiC/SiO2 nanochain heterojunction has been synthesized, the chained homogeneous nanostructure of SiC has not been reported before. Herein, the novel β-SiC nanochains are synthesized assisted by the AAO template. The characterized results demonstrate that the nanostructures are constructed by spheres of 25–30 nm and conjoint wires of 15–20 nm in diameters. Raman and photoluminescence measurements are used to explore the unique optical properties. A speed-alternating vapor–solid (SA-VS) growth mechanism is proposed to interpret the formation of this typical nanochains. The achieved nanochains enrich the species of one-dimensional (1D) nanostructures and may hold great potential applications in nanotechnology.

No MeSH data available.


a Low-magnification and b high-magnification HRTEM images of the SiC nanochains. The inset image in (a) is the corresponding SAED patterns.
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Figure 5: a Low-magnification and b high-magnification HRTEM images of the SiC nanochains. The inset image in (a) is the corresponding SAED patterns.

Mentions: Furthermore, HRTEM image (Figure 5) provides the detailed structural information of the products. As shown in Figure 5a, the perfect SiC nanochain has spherical size of 25–30 nm and wire between adjacent spheres of 15–20 nm. Also, the stacking faults could be clearly observed within the nanostructure marked by arrows, suggesting that the SiC crystal possess a high density of defects. Additionally, during the cooling process, the residual oxygen and SiO vapors in the reaction chamber would also react to produce SiO2, which will then diffuse, precipitate, and nucleate easily on the surface of SiC nanostructure, otherwise, as the activity of the SiC nanostructures at the nanoscale, the surface of the products may be oxidized to be SiO2 in small amounts at room temperature after the reaction. Finally, both of above two reasons may result in the formation of very thin amorphous SiO2 layer, as shown in Figure 5b SiC nanostructures are actually wrapped by a very uniform thin SiO2 layer of 2–5 nm. Figure 5b distinctly depicts the spacing within the crystal between two adjacent lattice planes is 0.252 nm, indicating the crystal grows along [111] direction. These values are in well agreement with the known values for β-SiC crystal. The inset image in Figure 5a shows the corresponding SAED patterns, the sharp and regular single diffraction spots clearly indicate that the crystallized structure which could be indexed to the cubic crystalline β-SiC.


Large-scale Synthesis of β -SiC Nanochains and Their Raman/Photoluminescence Properties
a Low-magnification and b high-magnification HRTEM images of the SiC nanochains. The inset image in (a) is the corresponding SAED patterns.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3211428&req=5

Figure 5: a Low-magnification and b high-magnification HRTEM images of the SiC nanochains. The inset image in (a) is the corresponding SAED patterns.
Mentions: Furthermore, HRTEM image (Figure 5) provides the detailed structural information of the products. As shown in Figure 5a, the perfect SiC nanochain has spherical size of 25–30 nm and wire between adjacent spheres of 15–20 nm. Also, the stacking faults could be clearly observed within the nanostructure marked by arrows, suggesting that the SiC crystal possess a high density of defects. Additionally, during the cooling process, the residual oxygen and SiO vapors in the reaction chamber would also react to produce SiO2, which will then diffuse, precipitate, and nucleate easily on the surface of SiC nanostructure, otherwise, as the activity of the SiC nanostructures at the nanoscale, the surface of the products may be oxidized to be SiO2 in small amounts at room temperature after the reaction. Finally, both of above two reasons may result in the formation of very thin amorphous SiO2 layer, as shown in Figure 5b SiC nanostructures are actually wrapped by a very uniform thin SiO2 layer of 2–5 nm. Figure 5b distinctly depicts the spacing within the crystal between two adjacent lattice planes is 0.252 nm, indicating the crystal grows along [111] direction. These values are in well agreement with the known values for β-SiC crystal. The inset image in Figure 5a shows the corresponding SAED patterns, the sharp and regular single diffraction spots clearly indicate that the crystallized structure which could be indexed to the cubic crystalline β-SiC.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Although the SiC/SiO2 nanochain heterojunction has been synthesized, the chained homogeneous nanostructure of SiC has not been reported before. Herein, the novel β-SiC nanochains are synthesized assisted by the AAO template. The characterized results demonstrate that the nanostructures are constructed by spheres of 25–30 nm and conjoint wires of 15–20 nm in diameters. Raman and photoluminescence measurements are used to explore the unique optical properties. A speed-alternating vapor–solid (SA-VS) growth mechanism is proposed to interpret the formation of this typical nanochains. The achieved nanochains enrich the species of one-dimensional (1D) nanostructures and may hold great potential applications in nanotechnology.

No MeSH data available.