Structural features and thermal stability of hollow-core Si nanowires: A molecular dynamics study
A molecular dynamics simulation with a Tersoff modified potential was used to investigate the structural features of hollow-core Si nanowires with outer radii of 1.6–3.8 nm at different temperatures. By utilizing the identifying diamond structure method and with analysis of the radial distribution f...
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| Published in: | Nano-Structures & Nano-Objects Vol. 29; p. 100822 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Elsevier B.V
01-02-2022
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | A molecular dynamics simulation with a Tersoff modified potential was used to investigate the structural features of hollow-core Si nanowires with outer radii of 1.6–3.8 nm at different temperatures. By utilizing the identifying diamond structure method and with analysis of the radial distribution function, we found that an increase in the cavity volume causes amorphization of the nanowires and may be associated with the large ratio of surface atoms to the total number of atoms in the nanowires. Typically, complete amorphization of hollow nanowires occurs when the wall thickness is comparable to the lattice constant of silicon. The simulation also showed that, for a given temperature, there is some threshold volume of the cavity, exceeding which leads to the complete amorphization of the nanowire. In addition, systematic work on the melting behavior of hollow-core Si nanowires was carried out. It was found that the melting of the Si hollow-core nanowires starts from the surface and rapidly extends to the inner regions of the nanowires as the temperature increases. The melting temperature of the Si nanowires was reduced by 200–500 K when the cavity volume fraction increased. It was observed that melting points decrease drastically in hollow-core nanowires with percentages of surface atoms above 50%. The present results provide a deep understanding of the different physical properties of hollow-core nanowires.
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•Molecular dynamics simulation work focuses on the structural behavior of hollow-core Si nanowires over a wide range of temperatures.•The effect of the cylindrical cavity volume fraction on the percentage of the crystalline phase in the hollow-core Si nanowires and the melting temperature is investigated.•The results show that with the increases of cavity volume fraction, both the stability and melting point of hollow-core nanowires were decreased.•This work provides additional insight in to understanding the structural and thermal stability of hollow-core nanowires. |
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| ISSN: | 2352-507X |
| DOI: | 10.1016/j.nanoso.2021.100822 |