SCIENCE / MEDICINE : GE Makes a Better Diamond

Researchers at General Electric Co. announced last week that they have devised a technique to make synthetic diamonds that are 10 times more transparent and that conduct heat 50% more efficiently than naturally occurring diamonds, which are generally considered the best heat conductors. The ability to carry away heat and to withstand high light intensities will make the new diamonds particularly valuable in the electronics and communications industries, and GE predicted an eventual $100-million annual market for them.

Diamond is a crystalline form of carbon. Naturally occurring diamonds are composed of about 99% carbon-12, the most common isotope of carbon, and 1% of the rarer form known as carbon-13. GE produced the new form by using at least 99.9% carbon-12.

The researchers employed a two-step process, first using conventional techniques to produce a thin diamond film containing only carbon-12. The film was then ground into a fine powder and crushed under millions of tons of pressure at a temperature of 2,500 degrees Fahrenheit. They obtained diamonds as large as one carat.