Electronic conductivity in gadolinium doped ceria under direct current as a trigger for flash sintering. (1st April 2020)

• Record Type: Journal Article
• Authors: Mishra, Tarini Prasad; Neto, Rubens Roberto Ingraci; Speranza, Giorgio; Quaranta, Alberto; Sglavo, Vincenzo M.; Raj, Rishi; Guillon, Olivier; Bram, Martin; Biesuz, Mattia
• Is Part Of: Scripta materialia. Number 179(2020)
• Page Start: 55
• Page End: 60
• Publication Date: 2020-04-01
• Subjects: Flash sintering -- Defects -- Onset of the flash -- Electro-chemical blackening -- Gadolinium-doped ceria; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.01.007
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: In this paper, we discuss the progression of flash sintering in 10mol% 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. Graphical abstract: Image, graphical abstract