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Researchers grow diamonds for industrial use


October 8, 1996
Web posted at: 1:50 p.m. EDT

From Correspondent Ann Kellan

BIRMINGHAM, Alabama (CNN) -- The word diamond comes from the Greek "adamas," meaning unconquerable. It is the Superman of all minerals -- the clearest and the hardest known.

Much more than a girl's best friend, the diamond is also a workhorse of industry. It is used in drill bits and cutting tools and to grind optical lenses. Now, efforts are under way to grow the super-hard minerals in the lab.

During Operation Desert Storm, sand blasted the infrared windows used by jet fighter pilots to see at night. The desert pebbles scratched the thick, clear navigational windows, turning them into opaque walls -- cloudy, gritty and dangerous for pilots in flight.


Lockheed Martin, maker of the window, funded a project at the University of Florida for researchers to find a way to protect the windows from such wear and tear. Their solution: a diamond coating.

Researcher Melanie Carasso said the coating is created by mixing a powder containing microscopic diamond particles, or seeds, with water. Into the solution goes a silicon wafer, treated so the diamond seeds will stick to it.

Then the wafer is microwaved in a chamber filled with carbon gases. The intense heat from the microwave breaks down the gases. And since diamonds are made of carbon, the carbon atoms from the gases are naturally attracted to and adhere to the diamond seeds on the silicon wafer, growing more diamond particles.

Once perfected, the researchers say, this technique can be used to coat a variety of surfaces, making them virtually scratch-proof. The future could include everything from diamond-coated kitchens to spacecraft windows.

One such window has already gone into space. An expensive, quarter-sized diamond-coated window endured extreme temperatures and conditions on one of the Pioneer probes to Venus in 1978.

The scientists are also trying to find ways to grow single crystal diamonds cheaper and faster.


At the University of Alabama, researchers grew a sixth of a carat onto a clear diamond by cranking up their microwave chamber to about 2,000 degrees.

"You can grow diamond at a rate of a human hair size in ten minutes," Yogesh Vohra, a professor of physics at the University of Alabama.

Even though researchers are increasing the speed at which diamonds grow, it is still very expensive to reproduce diamonds in the lab. A natural high grade, one-carat diamond may cost $6,300 out on the market -- but a similar synthetic would cost $10,000 to make in the lab.


Scientists hope one day to bring down the cost of making diamonds for use in computers, where circuitry heats up.

"If you've looked at most Pentiums in computers today, they get pretty hot," said Les Kramer of Lockheed Martin. "And if you took that fan off you'd burn them out in about two to three minutes."

Researchers believe that some day silicon microchips could be replaced by diamond chips, making for faster, more powerful computers that are able to take the heat.

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