Developments to Watch
MIX BUCKYBALLS AND GAS--AND PRESTO! DIAMOND FILM
Dieter M. Gruen is practicing his own kind of alchemy: transforming soot quickly into diamond films. Today, supertough diamond films are used sparingly: mainly to coat machine tools that cut aluminum-silicon alloys--the strong, lightweight materials used in cars. That's because a diamond film, a lattice of carbon atoms, is usually produced by a time- and energy-intensive process of stripping hydrogen atoms from carbon-containing methane gas. Inevitably, hydrogen ends up in the film, leading to defects.
To make his films, Gruen, a scientist at Argonne National Laboratory, uses pure soot: buckyballs, which contain 60 carbon atoms arranged in a hollow sphere. Microwaves excite a mixture of vaporized argon gas containing buckyballs. The liberated carbon atoms are then deposited in a thin, hydrogen-free film. The new process can produce films two to four times as fast as earlier methods, slashing production costs up to 50%, says Gruen. That could open up new uses for diamond films--to absorb heat from computer chips or serve as coatings for computer hard drives, for instance. Gruen says two electronics companies are negotiating research deals with Argonne to develop the films.EDITED BY EMILY T. SMITH