Room temperature ice discovered!

NEWS CENTER

Created: October 14, 2025 16:57

The frozen form of water we know on Earth is technically known as ice I. However, this is only one of more than 20 different phases of ice. Under different temperatures and pressures, water molecules can form very different crystal structures.

The newly discovered ice XXI stands out from all other phases with its tetragonal crystal structure, featuring large repeating units of 152 water molecules. This feature makes it unique both structurally and thermodynamically.

IMPOSSIBLE TO PRODUCE IN A HOME FREEZER

This intriguing shape isn't something you can replicate at home. Using a diamond anvil cell at the European XFEL facility in Germany, the researchers compressed water to 2 gigapascals of pressure—about 20,000 times atmospheric pressure at sea level—in just 10 milliseconds.

The pressure was then slowly released over a second, a process repeated hundreds of times. During this time, the X-rays took a million images per second, recording how the crystal structure changed.

THE MYSTERIOUS INTERMEDIATE STOP TO ICE VI

The data indicate that ice XXI is an intermediate stage that forms as the exotic phase of water transforms into ice VI. "Thanks to the unique X-ray pulses from the European XFEL," explains physicist Geun Woo Lee of the Korea Institute of Standards and Science , "we have uncovered multiple crystallization pathways for water molecules that are compressed and relaxed thousands of times by the dynamic diamond anvil cell."

CLUES TO THE UNIVERSE'S ICY WORLDS

The researchers say the discovery of ice XXI could help us understand not only the behavior of water on Earth but also the potential conditions on icy moons and planets. It's thought that many more ice phases, as yet unidentified, may exist on the moons of Neptune, Uranus, or Jupiter.