A new study by a team at the University of Chicago, published in the October 14, 2021 issue of the journal Nature Physics, reports on the creation of a new phase of ice called « superionic ice ». Turns out, the ice that tinkles in our glasses of Coke, known as Ih, is actually just one of at least 19 different phases of ice.
Formed from water, ice is comprised of only hydrogen and oxygen atoms in the famous H2O configuration of two hydrogen atoms attached to one oxygen atom.
One intriguing idea is that ice may become superionic when heated at very high temperatures and pressures. This exotic state would contain liquid-like hydrogen ions moving within a solid lattice of oxygen.
Superionic ice was first predicted in 1988, and since then a number of research groups have used simulation and static compression techniques to try and study this phase of ice.
The first experimental evidence for superionic water ice came from a 2018 study by scientists from the Lawrence Livermore National Laboratory (LLNL), UC Berkeley, and the University of Rochester. They first sandwiched a droplet of water between two diamonds that functioned like miniature anvils, squeezing the droplet with 2.5 GPa of pressure (25 thousand atmospheres). This « pre-compressed » water into the room-temperature ice VII, a cubic crystalline form of ice.
