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High‐Temperature Creep Behavior of Mixed Conducting La 0.5 Sr 0.5 Fe 1− x Co x O 3‐δ (0.5≤ x ≤1) Materials
Author(s) -
Lein Hilde Lea,
Wiik Kjell,
Einarsrud Mariann,
Grande Tor,
Laracurzio Edgar
Publication year - 2006
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.1551-2916.2006.01176.x
Subject(s) - creep , materials science , activation energy , exponent , oxygen , stress relaxation , grain size , thermodynamics , analytical chemistry (journal) , stress (linguistics) , atmospheric temperature range , relaxation (psychology) , mineralogy , composite material , chemistry , physics , psychology , social psychology , linguistics , philosophy , organic chemistry , chromatography
Steady‐state compressive creep rate of La 0.5 Sr 0.5 Fe 0.5 Co 0.5 O 3−δ (LSFC) and La 0.5 Sr 0.5 CoO 3−δ (LSC) is reported in the temperature region 900°–1050°C and stress range 5–28 MPa. The stress exponents for the two materials were 1.71±0.18 and 1.24±0.15, respectively. The activation energy for creep was considerably higher for LSC (619±56 kJ/mol) than for LSFC (392±28 kJ/mol). The grain size exponent for LSC was 1.28±0.14. Considerably higher creep rates were observed for both materials in N 2 compared with air. Relaxation by creep of chemical‐induced stresses in oxygen‐permeable membranes is addressed, especially at low partial pressure of oxygen.