In situ observations of a high-pressure phase of H2O Ice
A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.
I. Chou, 955 National Center, U.S. Geological Survey, Reston, VA 20192, USA. J. G. Blank, A. F. Goncharov, H. Mao, R. J. Hemley, Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad.
IM
Chou
JG
Blank
AF
Goncharov
H
Mao
RJ
Hemley