Phase transitions on the surface of a carbon nanotube

TL;DR

This paper demonstrates how carbon nanotube resonators can be used to study phase transitions and monolayer formation of noble gases on their surface, revealing insights into adsorption phenomena and electromechanical coupling.

Contribution

It introduces a novel method using nanotube resonators to investigate adsorption, phase transitions, and electronic effects on cylindrical surfaces.

Findings

Observation of monolayer formation on nanotubes

Detection of phase transitions within adsorbed monolayers

Modification of electrical conductance during adsorption

Abstract

A suspended carbon nanotube can act as a nanoscale resonator with remarkable electromechanical properties and the ability to detect adsorption on its surface at the level of single atoms. Understanding adsorption on nanotubes and other graphitic materials is key to many sensing and storage applications. Here we show that nanotube resonators offer a powerful new means of investigating fundamental aspects of adsorption on carbon, including the collective behaviour of adsorbed matter and its coupling to the substrate electrons. By monitoring the vibrational resonance frequency in the presence of noble gases, we observe the formation of monolayers on the cylindrical surface and phase transitions within these monolayers, and simultaneous modification of the electrical conductance. The monolayer observations also demonstrate the possibility of studying the fundamental behaviour of matter in cylindrical geometry.