Limits...
Effect of Peierls transition in armchair carbon nanotube on dynamical behaviour of encapsulated fullerene.

Poklonski NA, Vyrko SA, Kislyakov EF, Hieu NN, Bubel' ON, Popov AM, Lozovik YE, Knizhnik AA, Lebedeva IV, Viet NA - Nanoscale Res Lett (2011)

Bottom Line: The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory.It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude.The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.

View Article: PubMed Central - HTML - PubMed

Affiliation: Physics Department, Belarusian State University, pr, Nezavisimosti 4, Minsk 220030, Belarus. poklonski@bsu.by.

ABSTRACT
The changes of dynamical behaviour of a single fullerene molecule inside an armchair carbon nanotube caused by the structural Peierls transition in the nanotube are considered. The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory. Significant changes of the barriers for motion along the nanotube axis and rotation of these fullerenes inside the (8,8) nanotube are found at the Peierls transition. It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude. The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.

No MeSH data available.


Related in: MedlinePlus

Dependences of the diffusion coefficients on the reciprocal of temperature 1/T. (a, c) The diffusion coefficient Dd; (b) the diffusion coefficient Dr. (a, b) The C20 fullerene; (c) the Fe@C20 endofullerene. Solid lines: the (8,8) carbon nanotube with the Kekule structure; dashed lines: the (8,8) carbon nanotube with the structure of metallic phase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211273&req=5

Figure 6: Dependences of the diffusion coefficients on the reciprocal of temperature 1/T. (a, c) The diffusion coefficient Dd; (b) the diffusion coefficient Dr. (a, b) The C20 fullerene; (c) the Fe@C20 endofullerene. Solid lines: the (8,8) carbon nanotube with the Kekule structure; dashed lines: the (8,8) carbon nanotube with the structure of metallic phase.

Mentions: The temperature dependencies of the diffusion coefficients, Dd and Dr, estimated using expressions (2) are shown in Figure 6. The dependence of the interaction energy EW(z) on the displacement of the fullerene C20 has two different barriers between the neighbour minima for the case of the nanotube with the Kekule structure (see Figure 4a). Since the frequency of the jumps of the fullerene between the neighbour minima exponentially depends on the barrier, the contribution of jumps over the lower barrier into the total diffusion coefficient is disregarded in these estimations. The temperature range corresponding to the Peierls transition temperature estimates TP ≃ 1-15 K [4,5,8] and the cases ΔEd/kBT <1 and ΔEr/kBT <1, where the Arrhenius formula is adequate, are considered. (For rotation of the Fe@C20 inside the nanotube with the Kekule structure the Arrhenius formula is not applicable (ΔEr/kBT >1) at this temperature range; this case is considered below.) Figure 6 shows that the changes of the diffusion coefficients, Dd and Dr, at the Peierls transition can be of orders of magnitude. It is of interest that the diffusion coefficient Dr for rotational diffusion of the C20 fullerene decreases at the Peierls transition with the increase of temperature.


Effect of Peierls transition in armchair carbon nanotube on dynamical behaviour of encapsulated fullerene.

Poklonski NA, Vyrko SA, Kislyakov EF, Hieu NN, Bubel' ON, Popov AM, Lozovik YE, Knizhnik AA, Lebedeva IV, Viet NA - Nanoscale Res Lett (2011)

Dependences of the diffusion coefficients on the reciprocal of temperature 1/T. (a, c) The diffusion coefficient Dd; (b) the diffusion coefficient Dr. (a, b) The C20 fullerene; (c) the Fe@C20 endofullerene. Solid lines: the (8,8) carbon nanotube with the Kekule structure; dashed lines: the (8,8) carbon nanotube with the structure of metallic phase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211273&req=5

Figure 6: Dependences of the diffusion coefficients on the reciprocal of temperature 1/T. (a, c) The diffusion coefficient Dd; (b) the diffusion coefficient Dr. (a, b) The C20 fullerene; (c) the Fe@C20 endofullerene. Solid lines: the (8,8) carbon nanotube with the Kekule structure; dashed lines: the (8,8) carbon nanotube with the structure of metallic phase.
Mentions: The temperature dependencies of the diffusion coefficients, Dd and Dr, estimated using expressions (2) are shown in Figure 6. The dependence of the interaction energy EW(z) on the displacement of the fullerene C20 has two different barriers between the neighbour minima for the case of the nanotube with the Kekule structure (see Figure 4a). Since the frequency of the jumps of the fullerene between the neighbour minima exponentially depends on the barrier, the contribution of jumps over the lower barrier into the total diffusion coefficient is disregarded in these estimations. The temperature range corresponding to the Peierls transition temperature estimates TP ≃ 1-15 K [4,5,8] and the cases ΔEd/kBT <1 and ΔEr/kBT <1, where the Arrhenius formula is adequate, are considered. (For rotation of the Fe@C20 inside the nanotube with the Kekule structure the Arrhenius formula is not applicable (ΔEr/kBT >1) at this temperature range; this case is considered below.) Figure 6 shows that the changes of the diffusion coefficients, Dd and Dr, at the Peierls transition can be of orders of magnitude. It is of interest that the diffusion coefficient Dr for rotational diffusion of the C20 fullerene decreases at the Peierls transition with the increase of temperature.

Bottom Line: The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory.It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude.The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.

View Article: PubMed Central - HTML - PubMed

Affiliation: Physics Department, Belarusian State University, pr, Nezavisimosti 4, Minsk 220030, Belarus. poklonski@bsu.by.

ABSTRACT
The changes of dynamical behaviour of a single fullerene molecule inside an armchair carbon nanotube caused by the structural Peierls transition in the nanotube are considered. The structures of the smallest C20 and Fe@C20 fullerenes are computed using the spin-polarized density functional theory. Significant changes of the barriers for motion along the nanotube axis and rotation of these fullerenes inside the (8,8) nanotube are found at the Peierls transition. It is shown that the coefficients of translational and rotational diffusions of these fullerenes inside the nanotube change by several orders of magnitude. The possibility of inverse orientational melting, i.e. with a decrease of temperature, for the systems under consideration is predicted.

No MeSH data available.


Related in: MedlinePlus