Scientists discover new superionic ice phase under extreme conditions

A research team led by physicist Alexis Forestier has experimentally confirmed the existence of a superionic ice structure, a discovery that could explain the internal compositions of ice giants like Uranus and Neptune.

Using diamond anvil cells and laser heating, the scientists subjected water samples to extreme conditions: pressures of up to 230 gigapascals (approximately 2.3 million times Earth's atmospheric pressure) and temperatures reaching 2,357 degrees Celsius. Under these conditions, water does not turn into a gas but instead enters a superionic state characterized by a “tightly packed hexagonal” (hcp) crystal lattice.

In this exotic state of matter, the substance behaves as both a solid and a liquid. The oxygen atoms remain fixed in a solid crystalline lattice, while the hydrogen nuclei move freely through the structure, similar to particles in a liquid. This unique property may provide insights into the complex and asymmetrical magnetic fields observed on Uranus and Neptune.