Electronic conductivity in gadolinium doped ceria under direct current as a trigger for flash sintering

SCRIPTA MATERIALIA

卷:179

Article

Mishra, Tarini Prasad^1,2  Neto, Rubens Roberto Ingraci²  Speranza, Giorgio³  Quaranta, Alberto⁴  Sglavo, Vincenzo M.⁴  Raj, Rishi²  Guillon, Olivier^1,5  Bram, Martin¹  Biesuz, Mattia⁴ 

[1] Forschungszentrum Julich, Inst Energy & Climate Res Mat Synth & Proc IEK 1, D-52425 Julich, Germany

[2] Univ Colorado, Dept Mech Engn, Mat Sci & Engn Program, Boulder, CO 80309 USA

[3] Fdn Bruno Kessler, Via Sommarive 18, I-38123 Trento, Italy

[4] Univ Trento, Dept Ind Engn, Via Sommarive 9, I-38123 Trento, Italy

[5] Julich Aachen Res Alliance, JARA Energy, Julich, Germany

关键词: Flash sintering;    Defects;    Onset of the flash;    Electro-chemical blackening;    Gadolinium-doped ceria;   

DOI  :  10.1016/j.scriptamat.2020.01.007

来源: Elsevier

【 摘 要 】

In this paper, we discuss the progression of flash sintering in 10 mol% gadolinium-doped ceria specimens. Flash transition is correlated with the generation of n-type electronic conductivity in air under direct-current bias. Its origin is attributed to partial reduction of the material which propagates from the cathodic-to-anodic region. The phenomenon was observed, in-situ, by monitoring the development of electrochemical blackening during the incubation period of the flash-experiment. Anomalous features, including shift in the valence band edge, shrinkage of the band-gap and change in the oxidation state of Ce in flashed samples was confirmed by X-ray photoelectron spectroscopy and diffuse reflectance measurements. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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