Abstract
La0.2Sr0.8Cu0.1Fe0.9O3-δ and La0.2Sr0.8Cu0.2Fe0.8O3-δ both exhibit cubic perovskite structures with lattice parameters a = 0.38711 and 0.38694 nm, respectively. The initial oxygen non-stoichiometry, δ, of the as-synthesized materials was 0.24 for the sample with 10% Cu and 0.34 for 20% Cu. La0.2Sr0.8Cu0.1Fe0.9O3-δ has a lower p O (2) stability limit at 1x10-4 atm, whereas La0.2Sr0.8Cu0.2Fe0.8O3-δ starts to decompose at 1x10-3 atm. The conductivity is approximately 10 S cm-1 and it decreases with decreasing p O (2) from 1 atm to the lower p O (2) stability limit, following a 1/4 power p O (2) dependence for temperatures above 800 K. The activation energy in O2 is 1-2 kJ mol-1 and this increases to about 10 kJ mol-1 for the lower p O (2) limit. The Seebeck coefficient is very small, usually within ±15 μV K-1 of zero. Below 650 K, the weight is constant with temperature, whereas above 750 K δ increases with increasing temperature, causing an increase in thermal expansion. The thermal expansion coefficient below 650 K is approximately 15x10-6 K-1, and approximately 30x10-6 K-1 above 750 K.
Recommended Citation
I. Kaus and H. U. Anderson, "Electrical and Thermal Properties of La0.2Sr0.8Cu0.1Fe0.9O3-δ and La0.2Sr0.8Cu0.2Fe0.8O3-δ," Solid State Ionics, vol. 129, no. 1, pp. 189 - 200, Elsevier, Jan 2000.
The definitive version is available at https://doi.org/10.1016/S0167-2738(99)00325-2
Department(s)
Materials Science and Engineering
International Standard Serial Number (ISSN)
0167-2738
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Elsevier, All rights reserved.
Publication Date
01 Jan 2000