This is superionic ice. It is a highly electrically conductive material that may perhaps be the newest variety of ice discovered. This ice came into existence “at pressures between one and four million times that at sea level and temperatures half as hot as the surface of the sun”.
“Yes, we’re talking about ice,” says study leader Marius Millot, a physicist at Lawrence Livermore National Laboratory in California. “But the sample is at several thousand degrees.”
Normally unachievable here on Earth because certain conditions have to be met, this type of ice may exist on the planets Neptune and Uranus as these conditions are present in those planets. This might be able to explain how these distant planets mentioned work and what the origins of their unusual magnetic fields are.
Scientists already know of 17 varieties of crystalline ice… And more than 30 years ago, physicists predicted that crushing pressure should squeeze water into superionic forms.
Superionic materials are dual beasts, part solid and part liquid, that on a microscopic level consist of a crystal lattice permeated by free floating atomic nuclei that can carry electrical charge. In water—aka H2O—the oxygen atoms would crunch into a solidified crystal while the hydrogen’s protons would zip around like a liquid.
“It’s quite an exotic state of matter,” says coauthor Federica Coppari, also of the Livermore lab.
Last year, Millot, Coppari, and their colleagues found the first evidence for superionic ice, using diamond anvils and laser-induced shock waves to compress liquid water so much that it turned to solid ice for a few billionths of a second. The team’s measurements showed that the water ice briefly became hundreds of times more electrically conductive than it had previously been, a strong hint that it had gone superionic.
In their latest tests, the researchers used six giant laser beams to generate a sequence of shockwaves that crunched a thin layer of liquid water into solidified ice at millions of times Earth’s surface pressure and between 3,000 and 5,000 degrees Fahrenheit. Precisely timed x-ray flashes probed the configuration, which again only lasted for a few billionths of a second, and revealed that the oxygen atoms had indeed taken on a crystalline form.
Scientists have proposed to calling this new form of ice “Ice XVIII.” The name is not that catchy for me.
(Image Credit: Millot, Coppari, Hamel, Krauss (LLNL). Artist rendition.)