UAB and Carnegie Scientists Patent Process to Create Large Diamond Gemstones

What it takes nature to accomplish in thousands of years, University of Alabama at Birmingham (UAB) and Carnegie Institution of Washington scientists can now do in a matter of days. The team has patented a new apparatus and method to create large diamond gemstones in laboratories whose quality compares to those found in nature, and much more quickly

April 5, 2005

BIRMINGHAM, AL — What it takes nature to accomplish in thousands of years, University of Alabama at Birmingham (UAB) and Carnegie Institution of Washington scientists can now do in a matter of days. The team has patented a new apparatus and method to create large diamond gemstones in laboratories whose quality compares to those found in nature, and much more quickly.

In addition to retail applications, synthetic diamonds are used in high-pressure research, and applications in high temperature microelectronic devices are possible in the future, said co-patent holder Yogesh Vohra, Ph.D., physics professor and University Scholar in the UAB Department of Physics.

“People have been growing diamond gemstones for years, but our method is faster and uses microwave plasma technology,” Vohra said. “The patent covers the chemistry and apparatus, which is able to grow the diamond 100 to 200 times faster than conventional lab-created methods. We do not grow gem stones in our labs at UAB, but we have given industry the tools to do so.”

Vohra’s co-patent holders are Chih-shiue Yan, Ph.D., former UAB doctoral student and researcher at the Carnegie Institution, and fellow Carnegie researchers Russell Hemley, Ph.D., and Mao Ho-Kwang, Ph.D.

This new invention means the gemstone industry can grow diamonds of a carat weight rarely found in nature in a matter of days. The microwave plasma process also allows multiple crystals to be grown simultaneously.

“With the addition of boron in the microwave plasma, a large blue diamond like the Hope Diamond could be grown in the laboratory,” Vohra said.

The patented process uses nitrogen in the growth process that creates a yellow diamond that is heated under high pressure to produce a light yellow or nearly colorless crystal. Currently, Vohra and doctoral student Paul Baker, M.S., are working to develop white diamonds at a high growth rate so that the purification steps can be eliminated from the growth process.

Large-scale production of synthetic diamonds has long been an objective of both research and industry, Vohra said. Diamond, in addition to other advantageous properties, is the hardest known material, has the highest thermal conductivity of any other substance and is transparent to a wide variety of electromagnetic radiation. This means diamonds have abundant applications in a number of industries in addition to its value as a gemstone.

To this end, Vohra patented a process in May 1997 to grow synthetic diamonds by combining methane and hydrogen gases with high-powered microwaves. In February 2001, Vohra and UAB researcher Shane Aaron Catledge, Ph.D., were issued a patent for the process they developed that produces a smooth nanostructured diamond film that can be deposited on metals. That technology has evolved and has been licensed through the UAB Research Foundation by Birmingham-based Vista Engineering Inc. They are working to develop large-scale coating methods for nanostructured diamond-coated cutting tools for use by the automotive industry. The current market for these tools is approximately $780 million.