THE FEATURES OF SINGLE-WALLED CARBON NANOTUBES FORMATION ON METAL CATALYSTS: EXPERIMENTAL DATA AND THERMODYNAMIC CONSIDERATION

摘要

Carbon nanotubes attract considerable attention in fundamental and applied research ever since the discovery of multi-walled carbon nanotubes by Iijima in 1991 and the first synthesis of single-walled nanotubes (SWNTs) by arc discharge. SWNT studies are especially active and fruitful because this material shows unique mechanical, electronic and magnetic properties that were predicted theoretically and demonstrated experimentally. In the present study we used high resolution (HR) transmission electron microscopy (TEM) to obtain information about initial products of the SWNT arc discharge synthesis. "Sea-urchin" particles consisting of SWNT bundles growing radially from catalyst particles were identified as intermediate product of nanotubes growth (figure 1 A, B). To reveal factors affecting the nucleation process, we performed a thermodynamic analysis of carbon nucleation at metal surfaces.