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Influences of Temperature and Oxygen Partial Pressure on Mechanical Properties of La 0.6 Sr 0.4 Co 1− y Fe y O 3−δ
Author(s) -
Kimura Yuta,
Kushi Takuto,
Hashimoto Shinichi,
Amezawa Koji,
Kawada Tatsuya
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05265.x
Subject(s) - oxygen , analytical chemistry (journal) , valence (chemistry) , atmospheric temperature range , shear (geology) , moduli , phase transition , chemistry , bar (unit) , materials science , mineralogy , thermodynamics , composite material , physics , chromatography , organic chemistry , meteorology , quantum mechanics
Young's and shear moduli and Poisson's ratio of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ ( LSCF 6428), La 0.6 Sr 0.4 Co O 3−δ ( LSC ), and La 0.6 Sr 0.4 FeO 3−δ ( LSF ) were investigated in the temperature range from room temperature to 1173 K and in the oxygen partial pressure, P ( O 2 ), range from 1 × 10 −1 to 1 × 10 −4 bar by the resonance method. The Young's and the shear moduli decreased with increasing temperature at low temperatures and drastically increased at intermediate temperatures. The drastic increase was associated with the second‐order phase transition. In contrast, the Poisson's ratios of LSCF 6428, LSC , and LSF decreased around the phase transition temperature. The P ( O 2 ) dependence of the Young's and the shear moduli of LSCF 6428 showed different tendencies depending on temperature. At 873 K, the Young's and the shear moduli were almost independent of P ( O 2 ), whereas they increased with decreasing P ( O 2 ) at 973 K. At 1073 K, they first increased with decreasing P ( O 2 ) under higher P ( O 2 ) and then gradually decreased under lower P ( O 2 ). At 1173 K, they monotonically decreased with decreasing P ( O 2 ). Such complicated P ( O 2 ) dependence were interpreted by complex influences of the phase transition, the chemical expansion and the variation of the oxygen nonstoichiometry and the cation mean valence.