Helicity analysis of single, double, and triple helical iodine chains inside single-walled silicon carbide nanotubes

2017 ◽  
Vol 95 (8) ◽  
pp. 731-737 ◽  
Author(s):  
Zhen Yao ◽  
Chun-Jian Liu ◽  
Yi Li ◽  
Xiao-Dan Jing ◽  
Quan Yuan
Keyword(s):  
Silicon Carbide ◽  
Density Functional ◽  
Chain Structure ◽  
Field Analysis ◽  
Helical Chain ◽  
Functional Theory ◽  
Silicon Carbide Nanotubes ◽  
Helical Angle ◽  
Force Field Analysis ◽  
Chain Interaction

The helicity of encapsulated single, double, and triple helical iodine chains inside single-walled silicon carbide nanotubes is studied using the van der Waals interaction potential and density functional theory (DFT). Our results show that the optimal radius of the helical iodine chain increases linearly with tube radius, which produces a constant separation between the encapsulated chain and tube wall. The optimal helical angle cannot be determined with a single helical chain, due to the absence of the inter-chain interaction. For the double and triple helical chains, a small optimal helical angle can be induced by a large inter-chain interaction for the same tubes or a large tube for the same chain structure. We also find that the helicity is insensitive to the tube chirality. The DFT calculation further justifies our classical force field analysis and provides a more comprehensive understanding of this helical chains configuration.

STRUCTURAL AND ELECTRONIC PROPERTIES OF FINITE-LENGTH SINGLE-WALLED CARBON AND SILICON CARBIDE NANOTUBES: DFT STUDY

2013 ◽  
Vol 27 (29) ◽  
pp. 1350210 ◽  
Author(s):  
IGOR K. PETRUSHENKO ◽  
NIKOLAY A. IVANOV
Keyword(s):  
Silicon Carbide ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Functional Theory ◽  
Single Walled Carbon ◽  
Silicon Carbide Nanotubes ◽  
Structural And Electronic Properties ◽  
Walled Carbon Nanotubes

This paper presents a systematical analysis of the structure and electronic properties of armchair single-walled carbon nanotubes (SWCNTs) as well as single-walled silicon carbide nanotubes ( SiCNTs ) by using density functional theory. The geometries of all species were optimized at the B3LYP level of theory using the SVP basis set. The different behavior of C – C bonds "parallel" and "perpendicular" to the nanotube axis has been found. The HOMO–LUMO energy gap, ionization potential, electron affinity, electronegativity and hardness of studied tubes were compared. The influence of both SWCNTs and SiCNTs lengths on their electronic properties has been analyzed.

Electronic Structures of Vacancy Defective Chiral (6,2) SiC Nanotubes

2017 ◽  
Vol 896 ◽  
pp. 3-8
Author(s):  
Ke Jian Li ◽  
Hong Xia Liu
Keyword(s):  
Density Functional Theory ◽  
Silicon Carbide ◽  
Electronic Structures ◽  
Density Functional ◽  
First Principle ◽  
Defect Level ◽  
Functional Theory ◽  
Vacancy Defects ◽  
First Principle Calculations ◽  
Silicon Carbide Nanotubes

Vacancy defects are common defects formed in the syntheses of silicon carbide nanotubes (SiCNTs) and seriously impact the electronic structures of the nanotubes. With first-principle calculations based on density functional theory (DFT), vacancy defective (6,2) SiCNTs are studied. Vacancies form a pair of fivefold and ninefold rings. Carbon vacancy introduces an occupied defect level near the top of the valence band and an unoccupied level in the conduction band. Three defect levels are found in the band gap of the SiCNT with a silicon vacancy. These results are helpful for investigations on SiCNT devices and sensors.

Electronic Transport Properties of Single-Walled Zigzag Silicon Carbide Nanotubes with Antisite Defects

2011 ◽  
Vol 403-408 ◽  
pp. 1130-1134
Author(s):  
Jiu Xu Song ◽  
Hong Xia Liu
Keyword(s):  
Silicon Carbide ◽  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Exponential Relationship ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Silicon Carbide Nanotubes ◽  
Silicon Carbide Nanotube ◽  
Antisite Defects

The electronic transport properties are the basis for investigations on silicon carbide nanotube (SiCNT), which are suitable to develop novel nanometer electronic devices. The electronic transport properties of Single-Walled (8, 0) SiCNTs with antisite defects are investigated with the method combined Non-Equilibrium Green’s function with density functional theory. Results show that the similarity on electronic transport properties of the nanotube with different defects is high. Under a bias value greater than 1.0 V, a nearly exponential relationship between the bias and the current is achieved, which originates from more orbital participating in its transport properties caused by the increase of the bias.

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