Extreme nonequilibrium synthesis of a Ca-Cu-Si clathrate during the Trinity nuclear test

• 成果类型: Article
• 署名作者: Bindi, Luca; Mihalkovic, Marek; Widom, Michael; Steinhardt, Paul J.
• 署名单位: University of Florence; Slovak Academy of Sciences; Institute of Physics, SAS; Carnegie Mellon University; Princeton University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2604165123
• 发表日期: 2026-05-26
• 页码: e2604165123
• 关键词: clathrate; quasicrystal; Trinity test; extreme environments; crystal-structure; QUASI-CRYSTAL

摘要

The Trinity nuclear test of July 16, 1945, generated extreme transient conditions that produced trinitite, a silicate glass containing rare metallic phases. Here we report the discovery and structural and chemical characterization of a previously unknown Ca-Cu-Si type-I clathrate, (Ca3.3Cu0.4Fe0.3)(Sigma=4)Si-23, identified within a Cu-rich metallic droplet embedded in red trinitite. Single-crystal X-ray diffraction shows that this phase adopts the cubic clathrate-I topology, representing the first crystallographically confirmed clathrate structure documented among the solid-state products of a nuclear explosion. Beyond its intrinsic significance, this phase is notable for its close contextual association with the previously reported Si-rich icosahedral quasicrystal formed in the same detonation. Both phases formed under identical extreme conditions, occur within similar Cu-rich droplets, and share an unusually Si-rich Ca-Cu-Si-(Fe) chemistry, motivating an evaluation of whether the quasicrystal could be structurally derived from a clathrate framework. To evaluate this possibility, we performed density functional theory calculations on clathrate-based icosahedral models across a range of Cu contents. The results indicate that clathrate-derived icosahedral structures are mechanically plausible and metastable at low Cu concentrations (similar to 10 to 11%) but become unstable as Cu content approaches that of the Trinity quasicrystal. These findings constrain viable structural models for the quasicrystal and argue against a simple clathrate-derived interpretation.