Low-temperature structure and thermoelectric properties of ductile Ag2S0.4Te0.6. (15th April 2023)

• Record Type: Journal Article
• Authors: Li, Zhili; Zhang, Jiye; Wang, Shaoqin; Dong, Zirui; Lin, Chen; Luo, Jun
• Is Part Of: Scripta materialia. Number 228(2023)
• Publication Date: 2023-04-15
• Subjects: Thermoelectric materials -- Ductility -- Supercooled liquid -- Amorphous -- Silver chalcogenide; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2023.115313
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Ductile Ag2 S0.4 Te0.6 shows promising thermoelectric properties and interesting phase transitions and structural features above room temperature. In this work, our experiments reveal that Ag2 S0.4 Te0.6 is composed of a Ag2 Te-based glass and a Ag2 S-based supercooled liquid at room temperature. The Ag2 Te-based glass preserves its amorphous state in the measured temperature range (20–303 K), while the Ag2 S-based supercooled liquid crystallizes into a triclinic phase below 183 K, leading to respectively the glass and crystalline-like thermal transport of Ag2 S0.4 Te0.6 near room temperature and at low temperature. At the crystallization point of the Ag2 S-based phase, the electrical conductivity of Ag2 S0.4 Te0.6 shows an anomalous change. The extremely wide supercooling region (183–420 K) of the Ag2 S-based phase leads to the unprecedented ductility of Ag2 S0.4 Te0.6 . The thermoelectric figure of merit zT of Ag2 S0.4 Te0.6 increases monotonically with increasing temperature and reaches ∼0.17 at 300 K, showing the great potential as a ductile thermoelectric inorganic. Graphical abstract: The Ag2 S0.4 Te0.6 sample is composed of one Ag2 Te-based glass and one Ag2 S-based supercooled liquid at room temperature. The Ag2 Te-based glass maintains its amorphous state at low temperatures (20 -303 K), while the Ag2 S-based supercooled liquid crystallizes into a triclinic phase below 183 K, leading to unprecedented ductility, anomalous change in the electrical conductivity, as well as the glass/crystal mixture thermal transport of Ag2 S0.4 Te0.6 . Image, graphical abstract