Double perovskite Pr2CoFeO6 thermoelectric oxide: roles of Sr-doping and micro/nanostructuring

Wu, Hao and Shi, Xiao-Lei ORCID: https://orcid.org/0000-0003-0905-2547 and Liu, Wei-Di and Li, Meng and Gao, Han and Zhou, Wei and Shao, Zongping and Wang, Yifeng and Liu, Qingfeng and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 (2021) Double perovskite Pr2CoFeO6 thermoelectric oxide: roles of Sr-doping and micro/nanostructuring. Chemical Engineering Journal, 425:130668. ISSN 1385-8947


Abstract

Owing to their excellent thermal stability, non-toxicity, and low cost, oxide-based thermoelectric materials have considerably expanded research interests and industrial application. Here, we, for the first time, report a new-type Pr2CoFeO6 oxide-based thermoelectric materials from both theoretical and experimental aspects. Our first-principles calculation results indicate that Pr2CoFeO6 is a p-type semiconductor with narrow bandgap. The experimental thermoelectric evaluation shows that pristine Pr2CoFeO6, synthesized by a combination of sol-gel method and conventional sintering, has a peak figure of merit, ZT of 0.015 at 773 K with a high positive Seebeck coefficient of 250 μV K-1 and very low thermal conductivity of 0.7 W m-1 K-1 at this temperature. Further Sr2+ doping on Pr-sites (Pr3+) enhances the carrier concentration from 4.03×1014 cm-3 to 5.22×1017 cm-3, contributing to an improved power factor up to 46 μW m-1 K-2. Besides, Sr-doping induces point defects in the matrix and further suppresses the thermal conductivity to 0.58 W m-1 K-1, leading to a promising ZT up to 0.05 at 673 K in Pr1.8Sr0.2CoFeO6, which is significantly improved by 233 % compared to pristine Pr2CoFeO6. We also predict that a high ZT of >0.2 can be achieved by the optimization of carrier density, band engineering, and energy filtering, which is comparable to many other oxide-based thermoelectric materials.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 07 Jun 2021 03:13
Last Modified: 14 Jul 2021 06:59
Uncontrolled Keywords: thermoelectric; double perovskite; Pr2CoFeO6; band structure; nanostructure; calculation
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
Identification Number or DOI: https://doi.org/10.1016/j.cej.2021.130668
URI: http://eprints.usq.edu.au/id/eprint/42143

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