Skip to comments.New Technique Produces 10-carat Diamond
Posted on 05/16/2005 3:19:04 PM PDT by STARWISE
Crystal-clear material is better for optics, scientific applications
May 16, 2005
Researchers at the Carnegie Institution of Washington, D.C. have produced 10-carat, half-inch thick single-crystal diamonds at rapid growth rates (100 micrometers per hour) using a chemical vapor deposition (CVD) process. The size is approximately five times that of commercially available diamonds produced by the standard high-pressure/high-temperature (HPHT) method and other CVD techniques.
In addition, the team has made colorless single-crystal diamonds, transparent from the ultraviolet to infrared wavelengths with their CVD process.
Most HPHT synthetic diamond is yellow and most CVD diamond is brown, limiting their optical applications. Colorless diamonds are costly to produce and so far those reported are small. This limits general applications of these diamonds as gems, in optics, and in scientific research.
Last year, the Carnegie researchers found that HPHT annealing enhances not only the optical properties of some CVD diamond, but also the hardness. Using new techniques, the Carnegie scientists have now produced transparent diamond using a CVD method without HPHT annealing.
"High-quality crystals more than three carats are very difficult to produce using the conventional approach," said scientist Russell Hemley, who leads the diamond effort at Carnegie. "Several groups have begun to grow diamond single crystals by CVD, but large, colorless, and flawless ones remain a challenge. Our fabrication of 10-carat, half-inch, CVD diamonds is a major breakthrough."
The results were reported at the 10th International Conference on New Diamond Science and Technology, Tsukuba, Japan, on May 12, 2005, and will be reported at the Applied Diamond Congress in Argonne, Ill., May 18, 2005.
"The rapid synthesis of large, single-crystal diamond is a remarkable scientific achievement, and has implications for a wide range of scientific and commercial applications," said David Lambert, program director in the National Science Foundation (NSF)'s earth sciences division, which funded the research.
To further increase the size of the crystals, the Carnegie researchers grew gem-quality diamonds sequentially on the six faces of a substrate diamond plate with the CVD process. By this method, three-dimensional growth of colorless single-crystal diamond in the inch-range is achievable.
Finally, new shapes have been fabricated with the blocks of the CVD single crystals.
The standard growth rate is 100 micrometers per hour for the Carnegie process, but growth rates in excess of 300 micrometers per hour have been reached, and 1 millimeter per hour may be possible. With the colorless diamond produced at ever higher growth rate and low cost, large blocks of diamond should be available for a variety of applications.
"The diamond age is upon us," said Hemley.
Single-crystal diamond block formed by CVD process on six faces of a substrate diamond
The CVD process can produce a variety of single crystal diamonds.
AND I WANT A FEW OF THOSE BABIES ..;)
If they get good at making these flawless diamonds, would they be considered the same value as a natural flawless diamond?
Impressive! Thanks for posting this!
I wouldn't mind having a whole collection of them. :o)
Of course, I'll have to hock all the cameras and telescopes to afford the lens....
Probably not. No good reason why not though (rarity and "natural" being the only differentiating properties), just that people and markets are sometimes irrational.
Wow! Wow! Double-wow!
I'll take one in every color! ;-)
I guess we'll wait and see what happens, it will be interesting. I guess we'll be in trouble when we get good at making "gold" that is just like the real thing. ;)
Moore's law applies -- I bet -- we'll see diamond window panes in our lifetime.
We already can make gold. Better than 'traditional' gold.
"Finally, new shapes have been fabricated with the blocks of the CVD single crystals."
New shapes? They're "growing" diamonds that are faceted already? Or am I misunderstanding something here?
"If they get good at making these flawless diamonds, would they be considered the same value as a natural flawless diamond"
Depending on efficiency, the bottom could fall out of the diamond market.
Some people need their diamonds to come from the earth, just throw some dirt on it and raise the price.
When they come in cereal boxes then we'll be getting
This could have some interesting applications though.
I'm not interested unless it will cure cancer.
Who says size isn't everything, dahling?
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