Low thermal conductivity and thermoelectric properties of Si80Ge20 dispersed Bi2Sr2Co2Oy ceramics. Issue 3 (1st February 2023)

• Record Type: Journal Article
• Authors: Xia, Siyi; Song, Hongzhang; Liu, Shaohui; Hao, Haoshan
• Is Part Of: Ceramics international. Volume 49:Issue 3(2023)
• Page Start: 4707
• Page End: 4712
• Publication Date: 2023-02-01
• Subjects: Bi2Sr2Co2Oy ceramics -- Si80Ge20 dispersion -- Thermoelectric properties; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.09.360
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Bi2 Sr2 Co2 Oy is a thermoelectric material with low thermal conductivity. The Bi2 Sr2 Co2 Oy /Si80 Ge20 composite samples were prepared by solid phase sintering at high temperature to investigate the effects of Si80 Ge20 alloys as the second phase on the microstructure and thermoelectric properties of the fabricated composites. An appropriate amount of the dispersed Si80 Ge20 in the Bi2 Sr2 Co2 Oy matrix can reduce the resistivity of the composite successfully. In particular, the increase in phonon scattering caused by the second phase leads to a significant decrease in thermal conductivity, which improves the thermoelectric properties of the material significantly. At 923 K, the thermal conductivity of the Bi2 Sr2 Co2 Oy + 0.2 wt% Si80 Ge20 sample achieves an ultralow value of 0.58 W/K·m. Its corresponding optimal dimensionless thermoelectric figure of merit value is 0.36, which is 56% higher than that of the pure Bi2 Sr2 Co2 Oy sample.