In:
Journal of the American Ceramic Society, Wiley, Vol. 100, No. 6 ( 2017-06), p. 2690-2699
Abstract:
The oxygen nonstoichiometry of SrFeO 3−δ was determined by solid‐state Coulometric titration at 750°C‐1040°C and 10 −18 ≤ p O 2 (atm)≤0.5. At T ≤850°C, a hysteresis in the oxygen nonstoichiometry (δ) isotherms indicates the presence of a two‐phase region corresponding to a mixture of a perovskite and an oxygen vacancy ordered phase. The variation of δ with temperature at fixed p O 2 values and the variation of log( p O 2 ) with reciprocal temperature at fixed δ are reported. The p O 2 at the p ‐ n transition in the electrical conductivity increases as the temperature increases, and the transition in the conductivity isotherm occurs at a composition of SrFeO 2.505(1) at 950°C and SrFeO 2.508(1) at 900°C. Since strontium exclusively occupies the A‐site, a simple point defect model that assumes noninteracting defects can describe the isotherms but only at 1040°C; nonideal behavior is observed at lower temperatures. The partial molar thermodynamic quantities for oxygen in SrFeO 3−δ were determined.
Type of Medium:
Online Resource
ISSN:
0002-7820
,
1551-2916
DOI:
10.1111/jace.2017.100.issue-6
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
2008170-4
detail.hit.zdb_id:
219232-9
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