Kinetics of Topological Stone-Wales Defect Formation in Single Walled Carbon

TL;DR

This study investigates the formation kinetics of Stone-Wales defects in carbon nanotubes using density functional theory and transition state theory, revealing dependencies on nanotube properties and proposing methods to reduce activation barriers.

Contribution

It provides a detailed analysis of defect formation energies and barriers, highlighting their dependence on nanotube chirality, diameter, and defect orientation, and introduces strategies to lower activation barriers.

Findings

Kinetic barriers depend on nanotube chirality, diameter, and defect orientation.

A Brønsted-Evans-Polanyi correlation links formation energy and activation barrier.

Proposed methods to decrease kinetic activation barriers for defect formation.

Abstract

Topological Stone-Wales defect in carbon nanotubes plays a central role in plastic deformation, chemical functionalization, and superstructure formation. Here, we systematically investigate the formation kinetics of such defects within density functional approach coupled with the transition state theory. We find that both the formation and activation energies depend critically on the nanotube chairality, diameter, and defect orientation. The microscopic origin of the observed dependence is explained with curvature induced rehybridization in nanotube. Surprisingly, the kinetic barrier follows an empirical Br{\o}nsted-Evans-Polanyi type correlation with the corresponding formation energy, and can be understood in terms of overlap between energy-coordinate parabolas representing the structures with and without the defect. Further, we propose a possible route to substantially decrease the kinetic activation barrier. Such accelerated rates of defect formation are desirable in many novel electronic, mechanical and chemical applications, and also facilitate the formation of three-dimensional nanotube superstructures.