Unraveling The Mysteries Of Superionic Water

In the depths of the universe, a peculiar form of water has been discovered, one that may hold the key to understanding the enigmatic magnetic fields surrounding giant planets. This extraordinary state of water, known as superionic water, emerges when H2O is subjected to temperatures of several thousand degrees Celsius and pressures reaching millions of atmospheres.

Under these extreme conditions, the oxygen atoms form a rigid solid framework, while hydrogen ions move freely, creating an unusual phase of water that conducts electricity exceptionally well. Researchers have long suspected that superionic water could be the dominant form of water in the interiors of ice giant planets, such as Uranus and Neptune, which are believed to contain vast quantities of water.

A recent study has shed new light on the structure of superionic water, revealing a complex and disordered arrangement of oxygen atoms. Instead of forming a single, orderly pattern, the oxygen atoms assemble into a mixed structure that combines face-centered cubic regions with hexagonal close-packed layers. This hybrid and irregular sequence can only be detected using extremely precise measurement techniques made possible by advanced X-ray lasers. To uncover these details, researchers carried out two separate experiments at the Matter in Extreme Conditions (MEC) instrument at LCLS in the US and the HED-HIBEF instrument at European XFEL.