Superionic ice exists in liquid and solid form at the same time, forming at 4,725 degrees Celsius, roughly the same temperature as the surface of the Sun.
US scientists have successfully created superionic ice in the laboratory for the first time. The study results were published in February in the journal Nature Physics, according to Live Science.
Researchers have long thought that superionic ice, a high-pressure form of water ice, exists in the crusts of Uranus and Neptune, but that’s just a theory. “Our work provides experimental evidence for superionic ice and shows predictions that are not based only on simulations but actually reflect the special state of water under extreme conditions,” said Marius Millot, a researcher at the University of Michigan. physicist at Lawrence Livermore National Laboratory, said. Millot is the lead author of the study that describes the experiment that created the superionic ice.
The laser used in the super-ion ice-making experiment. (Photo: M. Millot/E. Kowaluk).
Researchers first predicted the existence of a strange water state that is both liquid and solid 30 years ago. Superionic ice is also much denser than regular ice because it only forms under extreme temperatures and pressures like the inside of a giant planet. In the superionic state, the hydrogen and oxygen in the water molecule have abnormal behavior. Hydrogen ions move like a liquid, inside a solid crystal lattice made of oxygen.
The process of superionic ice formation is very complex . First, the team compresses water into super-strong cubic ice crystals, unlike regular ice cubes. To do that, they used a diamond anvil to create a pressure of 2.5 gigapascals, about 25,000 times the air pressure on Earth. Next, the researchers heated and compressed the anvil more strongly under the influence of the laser. Each ice-crystal ice structure is irradiated with six lasers at 100 times higher pressure.
As soon as the superionic ice formed, the team quickly analyzed its optical and thermodynamic properties. They only have 10 – 20 nanoseconds to do the job before the pressure wave releases the compressive force that melts the ice. The team found that the ice melted at 4,725 degrees Celsius and at a pressure of 200 gigapascals. This pressure level is about two million times greater than the atmospheric pressure on Earth.
“It’s incredible that frozen water exists at thousands of degrees Celsius inside planets, but that’s what the experiment shows,” said Raymond Jeanloz, a planetary physicist at the University of California , Berkeley, study co-author, shared.
The new discovery could reveal the conditions inside Uranus and Neptune. Planetary scientists speculate that water makes up 65% of the cores of these planets, along with ammonia and methane.