Superheating gold beyond the predicted entropy catastrophe threshold

• 成果类型: Article
• 署名作者: White, Thomas G.; Griffin, Travis D.; Haden, Daniel; Lee, Hae Ja; Galtier, Eric; Cunningham, Eric; Khaghani, Dimitri; Descamps, Adrien; Wollenweber, Lennart; Armentrout, Ben; Convery, Carson; Appel, Karen; Fletcher, Luke B.; Goede, Sebastian; Hastings, J. B.; Iratcabal, Jeremy; Mcbride, Emma E.; Molina, Jacob; Monaco, Giulio; Morrison, Landon; Stramel, Hunter; Yunus, Sameen; Zastrau, Ulf; Glenzer, Siegfried H.; Gregori, Gianluca; Gericke, Dirk O.; Nagler, Bob
• 署名单位: Nevada System of Higher Education (NSHE); University of Nevada Reno; Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; Queens University Belfast; European XFEL; Columbia University; Princeton University; Princeton University; United States Department of Energy (DOE); Princeton Plasma Physics Laboratory; University of Padua; University of Oxford; University of California System; University of California Merced; University of Warwick
• 刊物名称: Nature
• ISSN/ISSBN: 0028-2515
• DOI: 10.1038/s41586-025-09253-y
• 发表日期: 2025-07-24
• 关键词: stability limit; electron; diffraction; matter

摘要

In their landmark study1, Fecht and Johnson unveiled a phenomenon that they termed the 'entropy catastrophe', a critical point where the entropy of superheated crystals equates to that of their liquid counterparts. This point marks the uppermost stability boundary for solids at temperatures typically around three times their melting point. Despite the theoretical prediction of this ultimate stability threshold, its practical exploration has been prevented by numerous intermediate destabilizing events, colloquially known as a hierarchy of catastrophes2, 3, 4-5, which occur at far lower temperatures. Here we experimentally test this limit under ultrafast heating conditions, directly tracking the lattice temperature by using high-resolution inelastic X-ray scattering. Our gold samples are heated to temperatures over 14 times their melting point while retaining their crystalline structure, far surpassing the predicted threshold and suggesting a substantially higher or potentially no limit for superheating. We point to the inability of our samples to expand on these very short timescales as an important difference from previous estimates. These observations provide insights into the dynamics of melting under extreme conditions.