Optimum sintering method and temperature for cold compact Bismuth Telluride pellets for thermoelectric applications

JOURNAL OF ALLOYS AND COMPOUNDS

卷:877

Article

Jaldurgam, Farheen F.^1,2  Ahmad, Zubair^2,3  Touati, Farid¹  Al Ashraf, Abdulla³  Shakoor, Abdul³  Bhadra, Jolly²  Al-Thani, Noora J.²  Han, Dong Suk³  Altahtamouni, Talal⁴ 

[1] Qatar Univ, Coll Engn, Dept Elect Engn, Doha 2713, Qatar

[2] Qatar Univ, Qatar Univ Young Scientist Ctr QUYSC, Doha 2713, Qatar

[3] Qatar Univ, Ctr Adv Mat CAM, Doha 2713, Qatar

[4] Qatar Univ, Coll Arts & Sci, Mat Sci & Technol Program, Doha 2713, Qatar

关键词: Bismuth telluride;    Thermoelectric;    Microwave sintering;    Conventional sintering;    Tube sintering;    Broadband dielectric broadband spectroscopy;   

DOI  :  10.1016/j.jallcom.2021.160256

来源: Elsevier

【 摘 要 】

This work intends to investigate the optimum sintering method and temperature that can improve the efficiency of bismuth telluride cold compact pellets, for the thermoelectric applications. Different p-type and n-type bismuth telluride cold compact pellets were treated using three different sintering techniques and conditions: pressure less (conventional), microwave, and tube (using argon environment) at temperatures 250 degrees C, 300 degrees C, 350 degrees C, and 400 degrees C. The structural, microscopic, electron transport, thermal, and dielectric properties of the pristine and sintered samples were examined. Broadband dielectric spectroscopy was performed to extract a detailed picture of the dielectric properties of the samples. Even though each type of sintering had its own merits and demerits, the optimum conditions for enhanced electric and thermal features were found in microwave furnace followed by tube and conventional. Low thermal conductivity of 0.4 W/m/K was observed in the samples sintered at 250 degrees C while the increase in sintering temperature from 250 degrees C to 300 degrees C improved the crystallinity of the material. Moreover, the crystal structure of the bismuth telluride altered with the occurrence of higher oxidation leading to the formation of high bismuth telluride oxide phases at sintering temperatures above 300 degrees C, more dominantly in the n type samples. (c) 2021 The Author(s). Published by Elsevier B.V. CC_BY_4.0

【 授权许可】

Free