Importance of Cr2O3 layer for growth of carbon nanotubes on superalloys

We present a detailed investigation of the formation of stable catalyst particles on Inconel substrates, an important step in the growth mechanism of carbon nanotubes on these substrates. The chemical nature of the interaction of catalyst and substrate was investigated using XPS, high-resolution cross-sectional TEM, and EDS studies. The results indicate that Cr2O3, an electrically conductive oxide, plays an important role in stabilizing nanoclusters of Fe catalyst under typical growth conditions. The nature of growth on a number of other superalloys is also presented and is examined with respect to their chemical composition. (C) 2009 Elsevier Ltd. All rights reserved.