Materials Research: Graphene Nanotubes Vibrate Collectively
IFF-News October 27, 2010
In awarding this year's Nobel Prize in Physics, the Nobel Prize Committee referred to graphene as a material with exceptional properties and huge potential for fabricating new materials and manufacturing innovative electronics. When a layer of graphene is rolled up to a seemless cylinder, a carbon nanotube is formed. The young investigators group of Dr Carola Meyer studied what happens if several of these tubes stick into each other. "The individual nanotubes do not behave independently of each other. They interact with their neighbours," said Meyer. These findings could help scientists create material properties that are suitable for developing the tiniest components in nanoelectromechanical systems. The results will be published in the November edition of NanoLetters and are already available online.
In order to measure the interaction, the researchers used a laser to excite the tubes into vibrational mode. The frequency of these vibrations was measured using Raman spectroscopy at TU Berlin. "However, this alone is not enough; we also had to know the diameter and number of the tubes involved. This is where collaboration in transmission electron microscopy with the Ernst Ruska-Centre was crucial," said Meyer. The coupling of the vibrations within a specific multiwalled tube was thus confirmed experimentally for the first time, and the coupling strength between the walls was determined. The work is published in the paper "Observation of Breathing-like Modes in an Individual Multiwalled Carbon Nanotube" and was funded by the German Research Foundation within the research group "Coherence and Relaxation Properties of Electron Spins".