Growth of straight nanotubes with a cobalt-nickel catalyst by chemical vapor deposition

In this letter, we report the catalytic synthesis of a large amount of stra ight carbon nanotubes using a transition-metal cobalt-nickel/zeolite cataly st. High-resolution transmission electron microscopy images show that they are well graphitized. Raman spectrum shows its peak at 1349 cm(-1) (D band) is much weaker than that at 1582 cm-(1) (G band). We believe that straight carbon nanotubes contain much less defects than curved nanotubes and might have potential applications in the future. (C) 1999 American Institute of Physics. [S0003-6951(99)00905-5].