High-pressure phases of SiO2 made in air by Fedoseev-Derjaguin laser process

Exposure of a falling stream of 1 μm average size α-quartz particles to a continuous wave or pulsed CO₂ laser beam in air resulted in the formation of a complete series of high-pressure phases of silica: coesite, stishovite, and apparently even denser forms with α-PbO₂ and Fe₂N structures. Since the laser exposure technique works with the carbon black to diamond transition, the technique is confirmed as a simple and generally applicable means to achieve the same effects as exposure to several hundred kilobars pressure.