Thin films of synthetic diamond are showing up on everything from drill bits to computer chips. Engineers praise the material's hardness, transparency, thermal conductivity, and resistance to radiation. Still, the more expensive natural, single-crystal diamonds have one edge over synthetic, polycrystalline ones: Electrons travel through them much more rapidly. That's important for fabricating electronic devices, such as transistors and detectors, from diamond films.
Now, in an article in the May 28 edition of Science magazine, researchers from Crystallume in Menlo Park, Calif., Lawrence Berkeley Laboratory, and Lawrence Livermore National Laboratory say there's hope. They say they produced polycrystalline diamond films through which electrons and their counterparts, positively charged "holes," can travel as rapidly as in single-crystal diamonds. They did it by reducing impurities and raising temperatures while laying down the films by chemical-vapor deposition. Crystallume staff scientist Mary Anne Plano says the films could be sensors for tracking the short-lived particles created in high-energy physics experiments. Indeed, the lead sponsor of the research was the Energy Dept.'s Superconducting Super Collider laboratory.