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KRISS Researchers Discover New Ice Phase Under Pressure

10/16/2025

Summary

KRISS Discovers Ice XXI

Korea Research Institute of Standards and Science (KRISS) researchers report ice XXI, forming under extreme pressure at room temperature.
Ice XXI has a tetragonal crystal structure and contains 152 water molecules.
The phase was identified with diamond anvil cells and X-ray facilities such as the European XFEL.
The findings were published in Nature Materials on October 10, 2025, noting its metastable nature and relevance to icy moons Titan and Ganymede.

Summary

KRISS Unveils Ice Formation

Researchers at the Korea Research Institute of Standards and Science (KRISS) generated two gigapascals of pressure within 10 milliseconds to study ice formation.
They achieved the pressure with diamond anvil cells.
They captured rapid X-ray flashes from the European XFEL every microsecond, creating a "movie" of ice formation.
The approach helps study how tightly packed molecules form ice at room temperature and clarifies ice variants under extreme conditions.

History

Historical Context

The discovery of Ice XI in 1972 marked a significant advancement in understanding ice's molecular structures, revealing its proton-ordered configuration. This research laid the groundwork for subsequent studies, including the recent identification of Ice XXI, formed under extreme pressure. These findings enhance our comprehension of ice variants and their potential roles in celestial bodies like Titan and Ganymede, crucial for planetary science and astrobiology.

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KRISS Discovers Ice XXI

Korea Research Institute of Standards and Science (KRISS) researchers report ice XXI, forming under extreme pressure at room temperature.
Ice XXI has a tetragonal crystal structure and contains 152 water molecules.
The phase was identified with diamond anvil cells and X-ray facilities such as the European XFEL.
The findings were published in Nature Materials on October 10, 2025, noting its metastable nature and relevance to icy moons Titan and Ganymede.

1 / 3