THERMOLYSIS OF C-60 THIN-FILMS YIELDS NI-FILLED TAPERED NANOTUBES

Highly graphitic needle-like elongated carbon nanotubes, containing en capsulated Ni, are produced by heating a sandwich consisting of altern ating thin films of C-60 and Ni deposited on a silica plate at 950 deg rees C. High-resolution transmission electron microscopy (HRTEM) studi es reveal that these tapered structures are almost completely filled w ith Ni and are closed at both ends. The diameters of the needles (2-5 mu m in length) range between 10-20 nm at one end and 30-200 nm at the other. A surprisingly high degree of graphitization is observed in th e walls of the nanotubes. These unique structures may prove useful as electrodes with various applications such as precision probes in biolo gical systems or scanning tunnelling microscope tips.