Researchers Discover a New (intermediate and Tetragonal) Form of Ice
Researchers at the University of Nevada, Las Vegas were trying to understand how water might behave under the high pressures inside distant planets. But along the way the team discovered a new form of ice, reports Phys.org, "redefining the properties of water at high pressures."Solid water, or ice, is like many other materials in that it can form different solid materials based on variable temperature and pressure conditions, like carbon forming diamond or graphite. However, water is exceptional in this aspect as there are at least 20 solid forms of ice known to us. A team of scientists working in UNLV's Nevada Extreme Conditions Lab pioneered a new method for measuring the properties of water under high pressure. The water sample was first squeezed between the tips of two opposite-facing diamonds - freezing into several jumbled ice crystals. The ice was then subjected to a laser-heating technique that temporarily melted it before it quickly re-formed into a powder-like collection of tiny crystals. By incrementally raising the pressure, and periodically blasting it with the laser beam, the team observed the water ice make the transition from a known cubic phase, Ice-VII, to the newly discovered intermediate, and tetragonal, phase, Ice-VIIt, before settling into another known phase, Ice-X.... While it's unlikely we'll find this new phase of ice anywhere on the surface of Earth, it is likely a common ingredient within the mantle of Earth as well as in large moons and water-rich planets outside of our solar system. The team's findings were reported in the March 17 issue of the journal Physical Review B.... The work also recalibrates our understanding of the composition of exoplanets, UNLV physicist Ashkan Salamat added. Researchers hypothesize that the Ice-VIIt phase of ice could exist in abundance in the crust and upper mantle of expected water-rich planets outside of our solar system, meaning they could have conditions habitable for life. Thanks to long-time Slashdot reader fahrbot-bot for sharing the story...
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