High-pressure amorphous nitrogen

The phase diagram and stability limits of diatomic solid nitrogen have been explored in a wide pressure-temperature range by several optical spectroscopic techniques, A narrow-g-ap semiconducting phase eta has been found to exist in a range of 80-270 GPa and 10-510 K. The vibrational and optical properties of the eta phase produced under these conditions indicate that it is largely amorphous and back transforms. to a new molecular phase. The band gap of the eta phase is found to decrease with pressure indicating possible metallization by band overlap above 280 GPa.