Pressure-induced structural transitions in multi-walled carbon nanotubes

TL;DR

This paper investigates how multi-walled carbon nanotubes deform under pressure, revealing a new radial corrugation mode that depends on their structure, with potential implications for their mechanical properties.

Contribution

It introduces the concept of radial corrugation in MWNTs under pressure and analyzes the critical conditions and modes of deformation using continuum elastic theory.

Findings

MWNTs undergo radial corrugation above ~1 GPa

Deformation modes depend on inner diameter and number of walls

Core-shell structure influences deformation behavior

Abstract

We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure $p_c \simeq 1$ GPa, above which the circular shape of the cross section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs.