Structural, electronic and elastic properties of zigzag carbon nanotubes

سال انتشار: 1399
نوع سند: مقاله کنفرانسی
زبان: انگلیسی
مشاهده: 471

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شناسه ملی سند علمی:

SDNCONF03_009

تاریخ نمایه سازی: 6 شهریور 1399

چکیده مقاله:

Density functional calculations have been carried out to predict the structural, electronic and elastic properties of zigzag (4, 0) carbon nanotube. The calculations were performed using the Full-Potential Linearized Augmented Plane Wave method with Generalized Gradient Approximation, Local Density Approximation and modified Becke-Johnson for the exchange-correlation functional. The structural properties such as lattice constant, bulk modulus, young s modulus, compressibility, bond lengths and the condensation of volume were calculated. The electronic properties of this carbon nanotube comprising of electronic band structure, density of states, effective atomic charge and electronic charge density were also estimated and analyzed. Young s modulus and the carbon-carbon bond lengths of (4, 0) CNTs were obtained 1.19 TP and 1.421, respectively. Moreover, the results show that the hardness of CNTs (4, 0) in three dimensions is less than the uniaxial hardness. In addition, the electronic properties demonstrate that these CNT shows metallic behavior. The electron charge densities diagram confirms that the carbon-carbon bonds in CNTs (4, 0) are covalent. Voight- Reuss- Hill approximations have been applied to estimate bulk modules, young s modulus, shear modulus, Poisson s ratio, elastic wave velocity, Debye temperature and melting temperature in the present study. Results predict that the Voight and Reuss approximations represent lower and upper limits of elastic properties. Calculations indicate that CNTs (4, 0) have large values for the elastic constants. The comparison between the bulk modules, young s modulus and shear modulus demonstrate the strength of CNTs along the nanotube axis. Moreover, it found that Poisson s ratio values is in contrast with other results due to the curvature effects in small diameter carbon nanotubes. Positive value of Poisson s ratio predict that elongation of the nanotube reduces its diameter. Calculated longitudinal elastic wave velocity is about fivefold as much as that of transverse wave. The Debye temperature and melting temperature have been estimated 2059.44 K and 2999.535 ± 300 K respectively.

نویسندگان

Hojat Allah Badehian

Department of Physics, Fasa University, Fasa, Iran

Khadijeh Gharbavi

Department of Physics, Shahid Chamran University, Ahvaz, Iran