Submission + - Scientists Create a New Form of Ice at 2,357 Degrees Celsius (sciencealert.com)
fahrbot-bot writes: Science Alert is reporting that Scientists have now demonstrated one of the weirdest forms of ice yet – under preposterous pressures up to 2.3 million atmospheres, and tremendous temperatures up to 2,630 kelvins (2,357 degrees Celsius, or 4,274 degrees Fahrenheit).
This superionic water ice is a deeply odd state of matter that's neither entirely solid nor entirely liquid. Its oxygen atoms remain fixed in a rigid crystal lattice, as they would in a solid. But the hydrogen nuclei are mobile, diffusing through that lattice more like particles in a liquid.
Researchers squeezed the samples between the tips of diamonds to pressures as high as 230 gigapascals, while using lasers to heat them to thousands of degrees. That's 2.3 million times Earth's atmospheric pressure at sea level – the pressure at the center of Earth, for context, is around 360 gigapascals.
Then, using an extremely narrow beam of synchrotron X-rays, they probed for changes in the crystal structure of the ice.
What emerged was a configuration predicted theoretically but never unambiguously observed in experiments: hexagonal close-packed, or hcp, ice. As the hcp crystal was heated, its expansion also showed a signature of superionic behavior, suggesting it entered the superionic state at around 1,700 kelvins.
Superionic ice is thought to exist deep inside Uranus and Neptune, where its unusual properties may play a role in generating the planets' equally unusual magnetic fields.
The findings have been published in Physical Review Letters: Observation of Hexagonal Close-Packed Water Ice at Conditions in Ice Giant Planetary Interiors
This superionic water ice is a deeply odd state of matter that's neither entirely solid nor entirely liquid. Its oxygen atoms remain fixed in a rigid crystal lattice, as they would in a solid. But the hydrogen nuclei are mobile, diffusing through that lattice more like particles in a liquid.
Researchers squeezed the samples between the tips of diamonds to pressures as high as 230 gigapascals, while using lasers to heat them to thousands of degrees. That's 2.3 million times Earth's atmospheric pressure at sea level – the pressure at the center of Earth, for context, is around 360 gigapascals.
Then, using an extremely narrow beam of synchrotron X-rays, they probed for changes in the crystal structure of the ice.
What emerged was a configuration predicted theoretically but never unambiguously observed in experiments: hexagonal close-packed, or hcp, ice. As the hcp crystal was heated, its expansion also showed a signature of superionic behavior, suggesting it entered the superionic state at around 1,700 kelvins.
Superionic ice is thought to exist deep inside Uranus and Neptune, where its unusual properties may play a role in generating the planets' equally unusual magnetic fields.
The findings have been published in Physical Review Letters: Observation of Hexagonal Close-Packed Water Ice at Conditions in Ice Giant Planetary Interiors
