Journal of the Ceramic Society of Japan
Online ISSN : 1348-6535
Print ISSN : 1882-0743
ISSN-L : 1348-6535
Full papers
Characterization of ZnO thermoelectric ceramics and their microstructures consolidated by two-step spark plasma sintering
Ahrong JeongMichitaka OhtakiByung-Koog Jang
Author information
JOURNAL OPEN ACCESS

2022 Volume 130 Issue 11 Pages 889-894

Details
Abstract

Zinc oxide (ZnO) thermoelectric ceramics were consolidated by spark plasma sintering (SPS) along with one-step/two-step sintering (OS/TS) temperature profiles, the latter employing a strategy of heating to a higher temperature (T1) followed by prolonged sintering at a lower temperature (T2) for densification while preventing grain growth. In the first step, the temperatures and holding times were 1100 and 1150 °C for 15 and 5 min, respectively, and the second-step was maintained at 1050 °C for 30, 60, and 120 min. By combining TS and SPS processes (TS-SPS), high relative densities of 91.4–94.9 % were achieved without significant grain growth. Electron backscatter diffraction (EBSD) revealed a noticeable grain-growth suppression of 56 % for the TS-SPS sample with T1 = 1100 °C. The highest power factor of 7.8 × 10−5 W K−2 m−1 was achieved for the TS-SPS ZnO, while the lowest thermal conductivity of 4.7 W K−1 m−1 was achieved for the OS-SPS ZnO, attaining a figure of merit (ZT) of 0.017 at 775 °C.

Content from these authors
© 2022 The Ceramic Society of Japan

この記事はクリエイティブ・コモンズ [表示 4.0 国際]ライセンスの下に提供されています。
https://creativecommons.org/licenses/by/4.0/deed.ja
Previous article Next article
feedback
Top