The journal Proceedings of the National Academy of Sciences published the results of research by American physicists. Scientists from Cornell University (USA) managed to find several new phases of changes observed during the crystallization of water ice.

The work was carried out by American scientists on a purely theoretical level, since most of all interest was aroused by ultra-high pressure indicators in the range of 10-50 million atmospheres. It is not possible to observe and predict the sequence of any stable or metastable structures, but such elements could well exist deep in the bowels of planets located outside the solar system.

Sequence of ice structures

A special model was used in the experiment, the observations of which showed that the structure of ice Pbcm (designation of the crystallographic group) under a pressure of 930 million Pascals is replaced by a new phase Pmc2 (1). With an increase in pressure and reaching its value of 1.3 TPa, the phase again changes to a new one – P2 (1), which remains quite stable with a wide range of pressure values ​​up to 4.8 TPa.

Plot of the relationship between pressure and volume for some new phases

Previous studies have shown that the transition to a metallized state occurs early enough. Moreover, the structures mentioned above belong to the class of insulating substances. The metallization of the structure in the last demonstrated experiment occurred only when the pressure value approached the 4.8 TPa mark. Scientists have noticed that under such conditions ice is already capable of transitioning into a state of a quantum fluid.