Hexatic phase in covalent two-dimensional silver iodide

• 成果类型: Article
• 署名作者: Bui, Thuy An; Lamprecht, David; Madsen, Jacob; Kurpas, Marcin; Kotrusz, Peter; Markevich, Alexander; Mangler, Clemens; Kotakoski, Jani; Filipovic, Lado; Meyer, Jannik C.; Pennycook, Timothy J.; Skakalova, Viera; Mustonen, Kimmo
• 署名单位: University of Vienna; Technische Universitat Wien; University of Silesia in Katowice; Slovak Academy of Sciences; Institute of Electrical Engineering, SAS; Eberhard Karls University of Tubingen; Eberhard Karls University Hospital; Eberhard Karls University of Tubingen; University of Antwerp; University of West Bohemia Pilsen
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adv7915
• 发表日期: 2025-12-04
• 页码: 1033-1037
• 关键词: GRAIN-BOUNDARY THEORY; liquid; transitions; identification; metastability; crystals; defects; ORDER

摘要

According to the Kosterlitz-Thouless-Halperin-Nelson-Young (KTHNY) theory, the transition from a solid to liquid in two dimensions proceeds through an orientationally ordered liquid-like hexatic phase. However, alternative mixed melting scenarios, in which melting proceeds through the hexatic phase with both continuous and discontinuous transitions, have also been observed in some two-dimensional systems. In this study, we imaged silver iodide embedded in multilayer graphene using time- and temperature-resolved in situ atomic-resolution scanning transmission electron microscopy and nanobeam electron diffraction. We observed the hexatic phase and provide evidence supporting a mixed melting scenario.