When a drop of water is placed on a very hot pan, it can skitter across the surface on a cushion of vapor, a phenomenon known as the Leidenfrost effect. This effect has now been observed on a much smaller scale, involving ice and an extremely hot surface. Scientists at the FXE instrument at European XFEL have discovered a related phenomenon where a 6-nanometer vapor barrier forms around ice when it is subjected to rapid heating, insulating it from the heat. This finding was published in the journal Communications Chemistry and challenges existing models of heat transfer. In the experiment, scientists heated a thin layer of platinum beneath an ultra-thin layer of amorphous ice, a noncrystalline, glassy form of ice. To their surprise, the ice did not warm or change structure quickly, even under intense heat. Using X-ray measurements and computer simulations, they found that a vapor gap, about 6 nanometers thick, formed between the platinum and the ice. This tiny gap acts as a thermal barrier, significantly reducing the flow of heat. This discovery shows that when materials are exposed to extremely rapid heating, the boundary where they meet can reorganize itself in unexpected ways. Tobias Eklund, a Ph.D. student at European XFEL and Johannes Gutenberg University Mainz (JGU), noted that the research revealed an anomalous interfacial energy transport mechanism. He explained that the formation of an insulating vapor layer was an unexpected result of studying the phase transitions of amorphous ice. Christopher Milne, group leader at the FXE instrument, emphasized the value of careful analysis and modeling in uncovering new scientific insights. The researchers are now interested in exploring whether similar insulating layers can form at other material interfaces under rapid heating conditions. Katrin Amann-Winkel, a principal investigator from JGU and group leader at the Max Planck Institute for Polymer Research, highlighted the broader implications of the study. She noted that understanding such phenomena is important for understanding the behavior of water and ice in both atmospheric and space environments, particularly where amorphous ice forms on tiny dust grains.