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.
Highlights
The structure and elastic properties of carbon nanotubes are studied in connection with the perspectives of their applications in nanoelectronic and nanoelectromechanical devices and composite materials, and are of fundamental interest, for physics of phase transitions
Superconductivity [1], commensurate-incommensurate phase transition in doublewalled nanotubes [2], spontaneous symmetry breaking with formation of corrugations along nanotube axis [3] and structural Peierls transition in armchair nanotubes [4,5,6,7,8,9] have been considered
We consider the possibility of inverse orientational melting for molecules encapsulated inside nanotubes caused by structural Peierls transition in the nanotubes
Summary
The structure and elastic properties of carbon nanotubes are studied in connection with the perspectives of their applications in nanoelectronic and nanoelectromechanical devices and composite materials, and are of fundamental interest, for physics of phase transitions. (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. The inverse orientational melting should be more prominent for the case of the Fe@C20 fullerene with the greater ratio of the barriers ΔErh/ΔErl. Let us discuss the possibility of observing the changes of the dynamical behaviour of molecules inside armchair carbon nanotubes at the Peierls transition. The Lennard-Jones potential is used for calculating the barriers for motion of the fullerenes along the axis and rotation about the axis of the (8,8) nanotube with the Kekule structure and the structure with all equal bonds corresponding to lowtemperature and high-temperature phases, respectively.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
