Team makes diamond breakthrough
Team makes diamond breakthrough
2008-11-14Newsfeed
Huge synthetic diamonds can now be made thanks to research by a team at the Carnegie Institute of Washington.
Huge synthetic diamonds can now be made thanks to research by a team at the Carnegie Institute of Washington.
The breakthrough in time, cost and quality will be a major boost to high-end technologies such as lasers and high-pressure anvils.
The new technique is so efficient that one immediate application will be to make ultra-high-quality windows that are optically transparent to lasers.
The team has perfected chemical vapour deposition (CVD), in which carbon atoms in a gas are deposited on a surface to produce diamond crystals.
Defects are then purged by a costly high-pressure, high-temperature treatment called annealing. But this can only produce relatively small diamonds.
The US team has got around the size limit by using microwaves to "cook" their diamonds in a hydrogen plasma at 2200C, but at low pressure. Diamond size is now limited only by the size of the microwave.
The improving quality of synthetic diamonds is threatening the natural diamond market. While 20 tonnes of natural diamonds are mined annually, 600 tonnes of synthetic stones are produced each year for industrial use alone.
Copyright © Press Association 2008
