Laser ablation

Guo et al. (1995) were the first to report the use of a laser to ablate a block of graphite mixed with catalytic metal. The catalytic metal can consist of elements such as Co, Nb, Pt, Ni, Cu, or a binary combination thereof. The composite block is formed by making a paste of graphite powder, carbon cement, and the metal. The paste is next placed in a cylindrical mold and baked for several hours. After solidification, the graphite block is placed inside an oven with a laser pointed at it, and Ar gas is pumped along the direction of the laser point. The oven temperature is approximately 1200° C. As the laser ablates the target, carbon nanotubes form and are carried by the gas flow onto a cool copper collector. Like carbon nanotubes formed using the electric-arc discharge technique, carbon nanotube fibers are deposited in a haphazard and tangled fashion.

Sources

Guo, T., et al., Chemical Physics Letters 243:49 (1995).