Scientists at the Carnegie Institution of Washington reported they have transformed nitrogen, normally a transparent gas, into an opaque solid by
subjecting the gas to immense pressure.
Russell Hemley, Mikhail Eremets, Ho-kwang Mao and Eugene Gregoryanz performed the research at Carnegie's Geophysical Laboratory. They used pressures
of up to 2.4 million times the atmospheric pressure at sea level to create the solid nitrogen, which can remain stable even when the pressure
returns to normal.
Team leader Hemley described the results as a "major breakthrough." For years, theorists have predicted that molecular nitrogen would become either a
semiconductor or a metal if subjected to pressures on the order of a million atmospheres.
Previous experiments have been limited in the amount of pressure that could be applied to nitrogen, and in the number of measurements that could be
performed on the material while under pressure. In this experiment, the researchers used newly developed techniques that allowed them to measure
electrical conductivity at very high pressures and various temperatures.
Physicist Chi-Chang Kao, of the Brookhaven National Laboratory, termed the breakthrough "quite important. The triple bond in the nitrogen
molecule is extremely strong. The Carnegie group has shown that you can break this bond in a laboratory setting for the
first time ever."
Kao told United Press International visible light can pass through gaseous nitrogen but not the more opaque, solid nitrogen formed by the Carnegie
team. In its solid state, nitrogen has available electrons that provide its semi-conducting properties.
Kao told UPI from Upton, Long Island, "It does store a large amount of energy and may have some military use -- perhaps some sort of new bomb."
"Such a dense form of solid nitrogen would reconfigure to its gaseous state very quickly," Lattman said. "In the process, it would release a
tremendous amount of energy and under the right conditions, could be used as an explosive. It would have to be kept at a very low
temperature, I would think, to remain solid at ambient pressures. Raising the temperature much would definitely create explosive conditions."
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