X-ray-induced dissociation of H2O and formation of an O-2-H-2 alloy at high pressure

Mao, Wendy L.; Mao, Ho-kwang; Meng, Yue; Eng, Peter J.; Hu, Michael Y.; Chow, Paul; Cai, Yong Q.; Shu, Jinfu; Hemley, Russell J.
2006
SCIENCE
DOI
10.1126/science.1132884
When subjected to high pressure and extensive x-radiation, water (H2O) molecules cleaved, forming O - O and H - H bonds. The oxygen (O) and hydrogen (H) framework in ice VII was converted into a molecular alloy of O-2 and H-2. X-ray diffraction, x-ray Raman scattering, and optical Raman spectroscopy demonstrated that this crystalline solid differs from previously known phases. It remained stable with respect to variations in pressure, temperature, and further x-ray and laser exposure, thus opening new possibilities for studying molecular interactions in the hydrogen-oxygen binary system.