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Updated: Oct 16, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Stoichiometric two-dimensional non-van der Waals AgCrS2 with superionic behaviour at room temperature
Jing Peng1, Yuhua Liu1, Haifeng Lv1,2
1Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Nanoscience, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) and CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei, People's Republic of China.
Abstract:
Layered materials have attracted tremendous interest for accessing two-dimensional structures. Materials such as graphite or transition metal dichalcogenides, in which the layers are held together by van der Waals interactions, can be exfoliated through a variety of processes in a manner that retains the structure and composition of the monolayers, but this has proven difficult for solids with stronger interlayer interactions. Here, we demonstrate the exfoliation of AgCrS2, a member of the AMX2 family (where A is a monovalent metal, M is a trivalent metal and X is a chalcogen), through intercalation with tetraalkylammonium cations, chosen for their suitable redox potential. The as-exfoliated nanosheets consist of Ag layers sandwiched between two CrS2 layers, similar to their structure in the bulk. They show superionic behaviour at room temperature, with an ionic conductivity of 33.2 mS cm-1 at 298 K that originates from Ag+ ions rapidly hopping between neighbouring tetrahedral interstices; in the bulk, this behaviour is only observed above 673 K.
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