Effect of plastic deformation on phonon thermal conductivity of α -Ag2S

Abstract

α-Ag2S is a ductile inorganic semiconductor recently identified, which can undergo considerable plastic deformation without the aid of dislocations. Together with its intrinsically poor electrical conductivity, it is one ideal system to study the effect of plastic deformation on phonon thermal transport. In this work, we show that the room temperature phonon thermal conductivity of α-Ag2S monotonically increases with compressive strain by about 32% at a compressive strain of 0.7. No deformation-induced phase transition occurs. Electrical conductivity and the Seebeck coefficient are basically invariant with deformation. No transport anisotropy is observed between the directions that are parallel and perpendicular to the compression direction. The stored energy in α-Ag2S measured by differential scanning calorimetry increases with strain but is remarkably larger than plastically deformed Cu at large strains. Possible origins for the increasing phonon thermal conductivity with plastic deformation are discussed. The present work provides original experimental observations on the effect of plastic deformation on phonon thermal conductivity, and it has important implications for the development of α-Ag2S-based ductile thermoelectric semiconductors and devices.

Achieving metal-like malleability and ductility in Ag2Te1-S inorganic thermoelectric semiconductors with high mobility

“…In addition, the room temperature electrical properties of the annealed Ag 2 Te 0.6 S 0.4 sample remain unchanged ( Figure S7 ), while the κ L increases after the compressive deformation. This anomalous trend suggests that the plastic deformation mechanism of Ag 2 Te 1- x S x materials is independent of the movement of dislocations, as reported in plastic α-Ag 2 S. 74 …”

Flexible Thermoelectric Reduced Graphene Oxide/Ag2S/Methyl Cellulose Composite Film Prepared by Screen Printing Process

“…The TE performance of the rGO/Ag2S/MC composite film was tested at a variable temperature, and the results are shown in Figure 5. When the temperature ≤ 440 K, the σ of the rGO/Ag2S/MC composite film was < 0.20 S/cm, mainly because MC is an insulating polymer, and the σ of α-Ag2S is also very low near RT [39]. When the temperature increased to 480 K, the σ of the rGO/Ag2S/MC composite film reached a maximum value of 228.78 S/cm, mainly due to the transformation from α-Ag2S to β-Ag2S and the fact that β-Ag2S has a higher σ [40].…”