High-temperature defect and crystal structure of perovskite type oxide ion conductor La0.8Sr0.2Ga0.8Mg 0.15Co0.05O3-δ

S. Nakayama, S. Hashimoto, K. Sato, K. Yashiro, K. Amezawa, J. Mizusaki

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

6 Citations (Scopus)

Abstract

A series of doped LaGaO3 perovskite type oxides is considered as the electrolyte of solid oxide fuel cells (SOFCs), due to their high oxide ionic conductivity. However, detailed defect chemistry, particularly the relationship between oxygen nonstoichiometry and lattice parameter under operating condition of SOFCs has not been understood well so far. To clarify the relationship, measurement was made on the oxygen nonstoichiometry of La 0.8Sr0.2Ga0.8Mg0.15Co 0.05O3-δ by high temperature gravimetry, and on the crystal structure by in-situ high temperature XRD. Oxygen vacancy concentration increases with decrease in log (P(O2)) and increase in temperature, finally converging on 3-δ=2.80. The large variation in the oxygen nonstoichiometry results from valence change of Co. The valence of Co at 3-δ=2.80 is nearly +2.0, whereas, the valence of Co at 3-δ=2.85 is considered close to +4.0. In-situ high temperature XRD confirmed that the oxygen vacancy formation led to increase in the lattice parameter, namely chemical expansion induced by oxygen nonstoichiometry.

Original languageEnglish
Title of host publicationECS Transactions - Solid Oxide Fuel Cells 11 (SOFC-XI)
Pages1701-1708
Number of pages8
Edition2 PART 2
DOIs
Publication statusPublished - 2009 Dec 1
Event11th International Symposium on Solid Oxide Fuel Cells (SOFC-XI)- 216th ECS Meeting - Vienna, Austria
Duration: 2009 Oct 42009 Oct 9

Publication series

NameECS Transactions
Number2 PART 2
Volume25
ISSN (Print)1938-5862
ISSN (Electronic)1938-6737

Other

Other11th International Symposium on Solid Oxide Fuel Cells (SOFC-XI)- 216th ECS Meeting
CountryAustria
CityVienna
Period09/10/409/10/9

ASJC Scopus subject areas

  • Engineering(all)

Fingerprint Dive into the research topics of 'High-temperature defect and crystal structure of perovskite type oxide ion conductor La<sub>0.8</sub>Sr<sub>0.2</sub>Ga<sub>0.8</sub>Mg <sub>0.15</sub>Co<sub>0.05</sub>O<sub>3-δ</sub>'. Together they form a unique fingerprint.

Cite this