The Korea Research Institute of Standards and Science (KRISS) has made a groundbreaking advancement in our understanding of water under extreme conditions, specifically under ultrahigh pressure exceeding 2 gigapascals (GPa) at room temperature. This unprecedented study has revealed the intricate behaviors of water during its freezing and melting processes, noted for taking place over microsecond timescales. The findings represent a significant leap in scientific exploration, uncovering what is now known as Ice XXI, an entirely new phase of ice.
In the realm of crystallization, ice has generally been observed to form when water temperatures fall below 0 °C. However, the complexities of phase transitions have been elucidated through this pivotal research. The KRISS team has demonstrated that water can crystallize into different forms even at room temperature or under conditions that exceed the boiling point. The study indicates that at pressures above 0.96 GPa, water transitions into Ice VI, hinting at a nuanced interplay between temperature and pressure that governs the crystallization landscape.
The research delved deep into the hydrogen-bonded architecture of water molecules, which undergo significant rearrangements during crystallization, leading to the emergence of various ice phases influenced by the environmental pressures and temperatures. The revelation that the existence of more than ten distinct ice phases occurs within the critical pressure range of 0 to 2 GPa underscores the complexity of ice structures and the potential for new materials with unique properties.
KRISS successfully achieved the generation of a supercompressed liquid water state—a state in which water remains liquid even at pressures over 2 GPa—using a state-of-the-art dynamic diamond anvil cell (dDAC). This innovative device allows for precisely controlled pressures to be applied to microscopic water samples, transforming the understanding of liquid behavior under extreme conditions while minimizing mechanical shocks that often accompany such experiments.
Conventional diamond anvil cells typically increase pressure by tightening assembly bolts, which can unintentionally induce nucleation. In contrast, the dDAC technique minimizes mechanical disturbance and dramatically shortens the time taken for compression to merely 10 milliseconds (ms). This technological innovation created an environment conducive for water to be compressed into Ice VI pressure ranges, marking a crucial step towards understanding the solid forms water can take.
The collaborative efforts between KRISS scientists and international partners resulted in capturing the crystallization process of supercompressed water with remarkable precision. The study was made possible through the integration of the dDAC technology with the European XFEL, the world’s largest X-ray free-electron laser facility, which provided high-resolution observations over microsecond timescales. Through these innovative methods, researchers were able to uncover multiple crystallization pathways which had previously eluded detection, showcasing the intricate nature of ice formation.
Among the significant discoveries is the identification of the new Ice XXI phase, which is characterized by its complex and sizable unit cell, a hallmark of its crystalline structure. This new ice’s architecture features a flattened rectangular design that distinguishes it from previously documented ice forms, highlighting the continual evolution of our understanding of water’s capabilities under strict conditions.
The research team, comprising experts from South Korea, Germany, Japan, the USA, and the UK, was spearheaded by Dr. Lee Geun Woo of KRISS. Their collective endeavor to unveil Ice XXI was marked by rigorous experimental design, data collection, and subsequent analysis, culminating in this monumental discovery that stands to reshape perspectives in both high-pressure research and material science.
The implications of this study stretch beyond the confines of our planet, as the density of Ice XXI is reminiscent of the high-pressure ice formations found within the icy moons of Jupiter and Saturn. This correlation opens avenues for deciphering the origins of life in extreme extraterrestrial environments, providing vital insights into the conditions that may support life beyond Earth.
Furthermore, the research not only enhances scientific comprehension of ice phases but also propels advancements in material creation, potentially leading to substance properties that are presently unimaginable. Following this groundbreaking study, Dr. Lee Yun-Hee remarked on the importance of these findings in terms of astrobiology, suggesting that understanding these extreme conditions may help in exploring life’s pathways under harsh environmental settings in space.
The integration of high-pressure physics with advanced observational techniques marks a pivotal moment in material science, underscoring the KRISS team’s commitment to pushing the boundaries of knowledge regarding the behaviors of water and ice. As researchers continue to explore ultrahigh-pressure contexts, the promise for new materials and deeper understanding of planetary phenomena remains immense.
In summary, this monumental breakthrough at KRISS has paved the way for further explorations into the discoverable realm of supercompressed states, revealing not just new phases but a broader array of possibilities for both scientific research and technology development in the years ahead.
Subject of Research: Multiple freezing-melting pathways of high-density ice through ice XXI phase at room temperature
Article Title: Multiple freezing-melting pathways of high-density ice through ice XXI phase at room temperature
News Publication Date: 10-Oct-2025
Web References: DOI link to article
References: None
Image Credits: Korea Research Institute of Standards and Science (KRISS)
Keywords
Ice XXI, ultrahigh pressure, water crystallization, diamond anvil cell, phase transitions, material science, astrobiology, KRISS, supercompressed liquid water, X-ray free-electron laser.
Tags: crystallization of water under pressureextreme conditions water studyhydrogen-bonded architecture of iceIce VI and Ice XXI comparisonIce XXI discoveryKRISS research advancementsmicrosecond timescale freezing and meltingnew phases of icephase transitions of waterroom temperature ice formationsignificance of Ice XXI in scienceultrahigh pressure effects on water
