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.