Researchers on the European XFEL and DESY are investigating uncommon types of ice that may exist at room temperature when subjected to excessive strain.
Ice is available in many types, even when fabricated from nothing however water molecules. Scientists have now recognized greater than 20 distinctive stable constructions, or “phases,” of ice, every with its personal molecular association. These variations are labeled with Roman numerals, reminiscent of ice I, ice II, and ice III.
In a current breakthrough, a global crew of researchers led by scientists from the Korea Analysis Institute of Requirements and Science (KRISS) has found a very new part often known as ice XXI. Utilizing superior X-ray services on the European XFEL and PETRA III, the crew captured and analyzed this beforehand unknown construction. Their findings have been printed in Nature Supplies.
Ice XXI is not like every other type of ice noticed to this point. It develops when liquid water is subjected to speedy compression, creating what scientists name “supercompressed water” at room temperature. This part is metastable, that means it may possibly persist for a time despite the fact that one other kind of ice would usually be extra steady below the identical circumstances. The invention gives worthwhile new insights into how ice behaves and transforms below excessive strain.
The Complexity of a Easy Molecule
Water or H2O, regardless of being composed of simply two parts, reveals outstanding complexity in its stable state. The vast majority of the phases are noticed at excessive pressures and low temperatures. The crew has discovered extra about how the totally different ice phases kind and alter with strain.
“Fast compression of water permits it to stay liquid as much as greater pressures, the place it ought to have already crystallized to ice VI,” KRISS scientist Geun Woo Lee explains. Ice VI is an particularly intriguing part, regarded as current within the inside of icy moons reminiscent of Titan and Ganymede. Its extremely distorted construction might enable advanced transition pathways that result in metastable ice phases.
As a result of most ice variants exist solely below excessive circumstances, the researchers created high-pressure circumstances utilizing diamond anvil cells. The pattern – on this case, water – is positioned between two diamonds, which can be utilized to construct up very excessive strain resulting from their hardness. Water was examined below pressures of as much as two gigapascals, which is about 20,000 instances greater than regular air strain. This causes ice to kind even at room temperature, however the molecules are far more tightly packed than in regular ice.
With a purpose to observe ice formation below totally different strain circumstances, the researchers first generated a excessive strain of two gigapascals inside 10 milliseconds (a millisecond is one thousandth of a second). They then launched the anvil cell over a interval of 1 second, then repeated the method. Throughout these cycles, the crew used the X-ray flashes of the European XFEL to seize photographs of the pattern each microsecond – one millionth of a second. With its extraordinarily excessive charge of X-ray pulses – working like a high-speed digital camera – they might make motion pictures of how the ice construction shaped.
Crystallizing the Discovery
Then, utilizing the P02.2 beamline at PETRA III, the researchers decided that ice XXI has a tetragonal crystal construction constructed of surprisingly massive repetitive models, known as unit cells.
“With the distinctive X-ray pulses of the European XFEL, now we have uncovered a number of crystallization pathways in H2O which was quickly compressed and decompressed over 1000 instances utilizing a dynamic diamond anvil cell,” explains Lee. “On this particular strain cell, samples are squeezed between the guidelines of two opposing diamond anvils and will be compressed alongside a predefined strain pathway,” states Cornelius Strohm from the DESY HIBEF crew that carried out this set-up on the Excessive Power Density (HED) instrument of European XFEL.
“The construction wherein liquid H2O crystallizes is dependent upon the diploma of supercompression of the liquid,” says Lee. “Our findings recommend {that a} larger variety of high-temperature metastable ice phases and their related transition pathways might exist, probably providing new insights into the composition of icy moons,” Rachel Husband from the DESY HIBEF crew provides.
Each DESY and European XFEL are making concerted efforts to raised perceive water: DESY by the joint effort Centre for Molecular Water Science, and European XFEL by its Water Name, from which this analysis was carried out. Sakura Pascarelli, Scientific Director at European XFEL notes: “It’s improbable to see one other nice consequence from our Water Name, an initiative inviting scientists to suggest modern research on water. We’re wanting ahead to many extra thrilling discoveries forward.”
Reference: “A number of freezing–melting pathways of high-density ice by ice XXI part at room temperature” by Yun-Hee Lee, Jin Kyun Kim, Yong-Jae Kim, Minju Kim, Yong Chan Cho, Rachel J. Husband, Cornelius Strohm, Emma Ehrenreich-Petersen, Konstantin Glazyrin, Torsten Laurus, Heinz Graafsma, Robert P. C. Bauer, Felix Lehmkühler, Karen Appel, Zuzana Konôpková, Minxue Tang, Anand Prashant Dwivedi, Jolanta Sztuck-Dambietz, Lisa Randolph, Khachiwan Buakor, Oliver Humphries, Carsten Baehtz, Tobias Eklund, Lisa Katharina Mohrbach, Anshuman Mondal, Hauke Marquardt, Earl Francis O’Bannon, Katrin Amann-Winkel, Choong-Shik Yoo, Ulf Zastrau, Hanns-Peter Liermann, Hiroki Nada and Geun Woo Lee, 10 October 2025, Nature Supplies.
DOI: 10.1038/s41563-025-02364-x
