University of Oulu

Yu, J., Nelo, M., Liu, X., Shao, S., Wang, B., Haigh, S. J., Jantunen, H., & Freer, R. (2022). Enhancing the thermoelectric performance of cold sintered calcium cobaltite ceramics through optimised heat-treatment. Journal of the European Ceramic Society, 42(9), 3920–3928.

Enhancing the thermoelectric performance of cold sintered calcium cobaltite ceramics through optimised heat-treatment

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Author: Yu, Jincheng1; Nelo, Mikko2; Liu, Xiaodong1;
Organizations: 1Department of Materials, University of Manchester, Manchester M13 9PL, United Kingdom
2Microelectronics Research Unit, University of Oulu, P. O. Box 4500, FI-90014, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 9.7 MB)
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Language: English
Published: Elsevier, 2022
Publish Date: 2022-09-13


Cold sintering is a promising technology for preparing electronic materials, enabling densification at low temperature, but rarely employed for thermoelectrics. Herein, high-quality Ca2.7Bi0.3Co3.92O9+δ ceramics were synthesised by a combination of cold sintering and annealing processes. Stoichiometric mixtures of raw materials were calcined once or twice at 1203 K for 12 h in air, and then cold sintered at 673 K for 60 min under a pressure of 85 MPa, followed by annealing at 1203 K for 12 h or 24 h in air. The effects of the calcination processes and annealing conditions on the thermoelectric performance of cold sintered samples were investigated. By optimising heat-treatment, the formation of secondary phases, texture development and porosity were controlled, leading to enhanced electrical conductivity and reduced thermal conductivity. Consequently, at 800 K there was 85% increase in power factor and 35% increase in ZT (value of 0.15) compared to previous studies.

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Series: Journal of the European Ceramic Society
ISSN: 0955-2219
ISSN-E: 1873-619X
ISSN-L: 0955-2219
Volume: 42
Issue: 9
Pages: 3920 - 3928
DOI: 10.1016/j.jeurceramsoc.2022.03.017
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: The authors are grateful to the EPSRC for the provision of funding for this work (EP/H043462, EP/I036230/1, EP/L014068/1, EP/L017695/1). The work was also supported by the Henry Royce Institute for Advanced Materials, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1. We appreciate the support from X-ray facilities in Department of Materials in the University of Manchester. Jincheng Yu gratefully acknowledges the financial support from China Scholarship Council. The work leading to these results has received funding from the European Research Council (ERC), ERC grant agreement No. 291132 and under the ERC POC grant agreement No. 812837. All research data supporting this work are directly available within this publication.
EU Grant Number: (812837) FUNCOMP - Fabricating Functional Components in Room Temperature
(291132) ULTIMATE CERAMICS - Printed Electroceramics with Ultimate Compositions
Copyright information: © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (