X-ray–Induced Dissociation of H2O and Formation of an O2–H2 Alloy at High Pressure
Wendy L. Mao,1
Ho-kwang Mao,2,3
Yue Meng,3
Peter J. Eng,4
Michael Y. Hu,3
Paul Chow,3
Yong Q. Cai,5
Jinfu Shu,2
Russell J. Hemley2
When subjected to high pressure and extensive x-radiation, water
(H
2O) 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.
2 Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
3 High Pressure Collaborative Access Team, Carnegie Institution of Washington, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
4 Consortium for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, USA.
5 National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan.
