Distinct termination morphologies for vertically aligned carbon nanotube forests

Abstract

Vertically aligned carbon nanotube forests, including single-walled nanotubes, are imagedoptically as they grow in situ from cobalt/alumina catalyst using water-assisted acetylenechemical vapor deposition. Three distinct termination morphologies are identified andinvestigated optically and via scanning electron microscopy. Quantitative growth dynamicsare extracted and show gradual deceleration and sudden termination of growth. Thetermination morphology is discussed in terms of the balance of forces within the forest. Wespeculate that sudden termination is a collective effect arising from an imbalance in theseforces.