Structural, thermal, surface, and electrical properties of Bi<sub>2</sub>O<sub>3</sub> ceramics co-doped with Er-Ho-Tb rare earths

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BALCI M.

JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY, vol.60, no.2, pp.385-397, 2024 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 60 Issue: 2
  • Publication Date: 2024
  • Doi Number: 10.1007/s41779-024-01007-9
  • Journal Name: JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Communication Abstracts, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.385-397
  • Keywords: Phase transition, X-Ray diffraction, Lattice shrinkage, Grain size, Differential thermal analysis
  • Erciyes University Affiliated: Yes

Abstract

Face-centered cubic-Bi2O3 (delta-phase) material is a better ion conductor when compared to other types of solid electrolytes that have been declared in the literature due to its anion-defective crystal configuration, and hence it can be a promising solid electrolyte choice for intermediate temperature SOFC applications. In this research, Er-Ho-Tb co-doped Bi2O3 compounds were successfully synthesized by the solid-state reaction method and characterized using the XRD, TG & DTA, FPPT, and FE-SEM techniques. Apart from sample 4Er4Ho4Tb, each sample became stable with a cubic delta-phase at room temperature, according to XRD patterns. The DTA curves revealed no exothermic or endothermic peaks, implying a phase change in the constant heating cycle. The conductivity of Ho-rich compositions was higher than that of others, confirming the impact of cation polarizability on conductivity. In addition, at 700 degrees C, the sample 4Er8Ho4Tb with 1:2:1 content ratios had the highest conductivity of 0.29 S/cm. The porosity on the grain boundaries increased with doping, leading to higher grain boundary resistance, which could be responsible for the conductivity drop.