Oxygen, for example, transforms to a shiny metal under ultra-high pressure. The Department of Energy's stockpile stewardship program will someday simulate the operation of a nuclear weapon with supercomputers. So scientists must learn how weapon materials behave under extreme pressures. Absent underground tests that produce a nuclear yield, other high-pressure physics experiments must provide this answer. They collaborated with Professor Yogesh Vohra and research associate Aaron Catledge at the University of Alabama.
Diamonds also can withstand ultra-high pressures.
But diamonds are relatively small. So an initial challenge is to make the samples size very small. Even more challenging is adapting instrumentation to investigate samples narrower than the width of a human hair, placed on a surface smaller than a pin-head, and squeezed under a pressure several million times the Earth's normal atmosphere. Sometimes the compression reaches the 3.6 million atmospheres estimated at the Earth's center. A technology for chemical vapor deposition of epitaxial diamond crystals allows fabrication on diamonds of miniature printed circuits that can withstand tremendous pressure, yet yield accurate results.