Thermochemistry and growth mechanism of SiC nanowires

Journal Article · Fri Sep 15 04:00:00 EDT 2017 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2017.06.009· OSTI ID:22742037

Chen, Jianjun ^[1]; Ding, Lijuan ^[1]; Xin, Lipeng ^[2]; Zeng, Fan ^[1]; Chen, Jun ^[3]

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1. Department of Materials Engineering, College of Materials and Textile, Zhejiang Sci-Tech University, Hangzhou 310018 (China)
2. Multi-disciplinary Materials Research Center, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an 710049 (China)
3. Intelligent Polymer Research Institute, University of Wollongong, Wollongong, NSW 2522 (Australia)

The chemical reaction thermodynamics and a novel two-stage growth mechanism of SiC nanowires synthesized by carbothermal reduction reactions were investigated based on the Si-C-O systems over a wide temperature range (1050 ≤ T ≤ 2000 K). The carbothermal reduction reaction process involves the fast formation of gaseous SiO and CO crucial intermediates, and the further carbon reduction of SiO to SiC. The relationship between the free energy changes and temperature at different pressures was also discussed. Some fundamental data in the work can help to analyze the thermochemistry of the carbothermal reduction reaction in the Si-C-O system, which is beneficial to optimize the temperature, pressure and the input precursors for controlling the SiC nanowire growth. - Graphical abstract: The chemical reaction thermodynamics of SiC nanowires synthesized by carbothermal reduction reactions was investigated, and a novel two-stage growth mechanism was proposed. The growth mechanism involved the formation of initial SiC embryos by heterogeneous nucleation and the growth of SiC nanowires by a gas-phase reaction. The process involved the fast formation of gaseous SiO and CO crucial intermediates, and the further carbon reduction of SiO to SiC. Display Omitted - Highlights: • The chemical reaction thermodynamics of SiC nanowires are investigated. • A novel two-stage growth mechanism of SiC nanowires is proposed. • The initial SiC particles/embryos can be formed by heterogeneous nucleation. • The gas-phase reaction of SiO and CO is the crucial step for the SiC nanowire growth.

• OSTI ID: 22742037
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 253; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CARBON MONOXIDE
FREE ENERGY
NANOWIRES
REDUCTION
SILICON CARBIDES
SILICON OXIDES
TEMPERATURE RANGE
THERMODYNAMICS