Graphene controlled phase evolution in Sr-deficient Sr(Ti, Nb)O3 thermoelectric ceramics

Jia Li; Cao Wu; Jilong Huang; Juanjuan Xing; Yuchi Fan; Qingqiao Fu; Ying Jiang; Hui Gu

Journal of Materiomics (Mar 2021)

Graphene controlled phase evolution in Sr-deficient Sr(Ti, Nb)O3 thermoelectric ceramics

Jia Li,
Cao Wu,
Jilong Huang,
Juanjuan Xing,
Yuchi Fan,
Qingqiao Fu,
Ying Jiang,
Hui Gu

Affiliations

Jia Li: Materials Genome Institute, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
Cao Wu: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
Jilong Huang: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
Juanjuan Xing: Materials Genome Institute, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China; Corresponding author.
Yuchi Fan: State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China; Corresponding author.
Qingqiao Fu: Materials Genome Institute, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
Ying Jiang: Materials Genome Institute, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
Hui Gu: Materials Genome Institute, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China; Corresponding author.

Journal volume & issue: Vol. 7, no. 2
pp. 366 – 376

Abstract

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Correlated phase and microstructural evolution are systematically investigated by electron microscopies in Sr-deficient Sr(Ti, Nb)O3 (STNO) thermoelectric ceramics incorporated with different fraction of reduced graphene oxide (RGO). It is found that while no impurity except for very few Ti3O5 precipitates are observed in monolithic STNO, the Nb-enriched rutile TiO2 appears in RGO/STNO composites. With increasing RGO content, the amount of precipitates increase at first and then decrease when RGO content becomes high, which can be ascribed to the formation of local Magnéli phase. In addition, the energy-dispersive X-ray spectra combined with cathodoluminescence characterization indicates that the variation of Sr deficiency experiences the opposite trend with respect to the precipitates content. These findings clearly reveal the unique reducing effect of RGO on the microstructure of doped SrTiO3 with Sr deficiency, which can greatly facilitate the design of perovskite based thermoelectric materials of hierarchical structure.

Published in Journal of Materiomics

ISSN: 2352-8478 (Print); 2352-8486 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.sciencedirect.com/journal/journal-of-materiomics

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