# Structural Properties of Double-Walled Carbon Nanotubes driven by Mechanical Interlayer Coupling

## TL;DR

This paper presents a new method for identifying the structure of double-walled carbon nanotubes using advanced electron microscopy, revealing non-random orientations due to mechanical coupling influenced by atomic-scale interactions.

## Contribution

It introduces a robust structural identification procedure for DWNTs and demonstrates the existence of mechanical interlayer coupling affecting tube orientations.

## Key findings

- Inner and outer tubes are not randomly oriented.
- Mechanical coupling influences tube orientation.
- Structural dependencies on diameters and helicities.

## Abstract

Structural identification of double-walled carbon nanotubes (DWNT) is presented through a robust procedure based on the latest generation of transmission electron microscope, making possible a statistical analysis based on numerous nano-objects. This approach reveals that inner and outer tubes of DWNTs are not randomly oriented, suggesting the existence of a mechanical coupling between the two concentric walls. With the support of atomic scale modelisations, we attribute it to the presence of incommensurate domains whose structures depend on the diameters and helicities of both tubes, and where inner tubes try to achieve a local stacking orientation to reduce strain effects.