Improvement of grain-boundary conductivity of trivalent cation doped barium zirconate

Susumu Imashuku, Tetsuya Uda, Yositaro Nose, Yasuhiro Awakura

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The sintering behavior of 15% scandium or yttrium doped barium zirconate (BaZr0.85Sc0.15O3-δ or BaZr 0.85Y0.15O3-δ) was investigated. Large and uniform grains were observed in 15% scandium-doped barium zirconate by sintering for 24 hours. This is because the phase relationship of 15% scandium-doped barium zirconate does not change between 1300 and 1600 °C. In contrast, typical microstructures of 15% yttrium-doped barium zirconate sintered for between 4 and 24 hours at 1600 °C were bimodal. This is because the phase relationship of 15% yttrium-doped barium zirconate changes between 1300 and 1600 °C. It takes a long time to obtain large and uniform grains of BaZr0.85Y0.15O3-δ. Also, scandium and yttrium co-doped barium zirconate (BaZr0.85ScxY 0.15-xO3-δ(x=0, 0.05, 0.075, 0.10, 0.15)) have been investigated in terms of phase relationship, microstructures, and electrical conductivity. The bulk conductivity of the scandium and yttrium co-doped barium zirconate increased with the dopant ratio of yttria. As for grain-boundary conductivity, BaZr0.85Sc0.05Y0.10O 3-δ had the highest grain-boundary conductivity among the scandium and yttrium co-doped barium zirconates in our study. From the observation of microstructure and results of grain boundary-conductivity measurement, we can say that yttrium is a dopant which increases specific grain-boundary conductivity and bulk conductivity, and scandium is a dopant which increases the grain size. Thus, there is a trade-off relationship between the grain size and specific grain-boundary conductivity based on the mixing ratio of scandium to yttrium.

Original languageEnglish
Title of host publicationThe Minerals, Metals and Materials Society - 3rd International Conference on Processing Materials for Properties 2008, PMP III
Pages207-212
Number of pages6
Publication statusPublished - 2009 Dec 1
Externally publishedYes
Event3rd International Conference on Processing Materials for Properties 2008, PMP III - Bangkok, Thailand
Duration: 2008 Dec 72008 Dec 10

Publication series

NameThe Minerals, Metals and Materials Society - 3rd International Conference on Processing Materials for Properties 2008, PMP III
Volume1

Other

Other3rd International Conference on Processing Materials for Properties 2008, PMP III
CountryThailand
CityBangkok
Period08/12/708/12/10

Keywords

  • Barium zirconate
  • Co-doping
  • Grain-boundary conductivity
  • Sinterability

ASJC Scopus subject areas

  • Materials Science(all)

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