Researchers Identify Hexagonal Close-Packed Ice Phase at Extreme Pressures
A team led by Alexis Forestier has successfully created hexagonal close-packed (HCP) ice in a laboratory setting, achieving conditions that mimic the interiors of ice giants like Neptune and Uranus. Using a diamond anvil cell and synchrotron X-ray diffraction, the researchers compressed water to over 200 GPa and heated it to approximately 2,000 K. This new phase, distinct from previously known forms like body-centered cubic (BCC) and face-centered cubic (FCC) ice, provides critical data for modeling planetary cores. The findings, published in Physical Review Letters, expand the known phase diagram of water and offer new constraints for understanding the deep interiors of gas giants, where direct observation is impossible.
