Alchemy has long been a fascination of mankind. Trying to make precious metals out of common substances has been an obsession for people since medieval times. Developments in the world of scientific research are helping to bring the concept to reality with regard to one of the world’s most precious substances – diamond.
While diamond was first synthesized in the laboratory in the early 1950s by General Electric, the technology was not commercialized until recent years. A handful of labs using different methods are now in business selling synthetic, laboratory grown diamonds. HTHP which employs high temperature and high pressure, and CVD using a chemical vapor deposition technique are currently the primary commercial means used to synthesize diamonds. Both techniques are expensive, relatively slow and are limited in terms of the size and quality of diamonds they produce.
Two new developments of interest may serve to accelerate the growth of the synthetic diamond industry. A group of Silicon Valley entrepreneurs have reportedly developed a technique to grow diamonds 150 times faster than current CVD technologies, and researchers at North Carolina State University have apparently grown diamond using an altogether different approach which is conducted at room temperatures and pressures. In the process, the NC State researchers have identified a new form of carbon called Q-Carbon.
The founders of Nanosolar are utilizing new plasma techniques developed in manufacturing solar panels in order to grow diamonds more quickly. The synthetic diamond is grown by CVD over a substrate of natural diamond. They have set up a company called Diamond Foundry to market their synthetic diamonds in jewelry.
scanning electron microscopy image of microdiamonds made by researchers at N C State University
In the case of NC State the researchers have reportedly created diamond on substrates of sapphire, glass and plastic, coated with amorphous carbon. A laser pulse is applied to the carbon coated material generating super high temperature for nanoseconds and then cooling rapidly. In the process crystalized diamond is created. The so called “Q-Carbon” is a new form of carbon not previously known. “We’ve now created a third solid phase of carbon,” according to Jay Narayan, the John C. Fan distinguished chair professor of materials science and engineering at NC State and lead author of three papers describing the work. “The only place it may be found in the natural world would be possibly in the core of some planets.”
This technique holds the promise of being much more affordable. According to Mr. Narayan, “We’re basically using a laser like the ones used for laser eye surgery. So, not only does this allow us to develop new applications, but the process itself is relatively inexpensive.”
Synthetic diamonds have the same optical and physical properties as natural diamond but can be identified as laboratory grown. Synthetic ruby and sapphire have been manufactured since the early 1900’s and have not diminished demand for their natural, mined counterparts.