Interaction between transition metals Co, Fe and Ni and carbon materials, such as multi-walled carbon nanotubes (MWNTs), single-walled carbon nanotubes (SWNTs), activated carbon (AC) and layered graphite (LG), has been investigated at high temperatures. Complete wetting for AC, partial wetting for MWNTs, and almost no wetting for SWNTs and LG have been observed, respectively. It is found that the defects in the carbon materials play a key role in the interaction. (C) 2002 Elsevier Science B.V. All rights reserved.