Carbon-nanotube tips with edge made of a transition metal

We show that transition metal atoms, when in contact with the open ends of single-wall carbon nanotubes can form stable tip structures. This allows one to combine the superior elastic and mechanical behavior of the nanotubes with the excellent electronic and electrical properties of transition metal systems to make high quality atomistic scanning probes for various nanotechnological applications. The geometry of the tip as well as the nature of the electronic states at the tip are found to be determined by the type of the transition metal atoms. We propose optimal tip materials for efficient probes based on a detailed electronic structure analysis using ab initio methods. (C) 2005 American Institute of Physics.