Abstract
The results of electrical conductivity and thermopower measurements are presented for selected (La,Ca)(Cr,Co)O3 compositions. The La1 - xCaxCrO3 compounds are typical p-type small polaron conductors. The La1 - xCaxCrO3 compounds are found to be small polaron conductors at room temperature for x ≤ 0.20 with a higher electrical conductivity than the corresponding chromite's. The electrical conductivity at room temperature is lower for Co-rich compositions than for Cr-rich compositions for compositions containing 10 mol% and 20 mol% Ca. This fact is attributed to the trapping of p-type small polarons at energetically lower Cr sites, resulting in a broad room temperature conductivity minimum. Above room temperature, the electrical conductivity increases with increasing Co content for all compositions. The thermopower for these compounds is interpreted using the Verwey electronic compensation mechanism including thermally activated disproportionation among Co ions. © 1995.
Recommended Citation
S. R. Sehlin et al., "Electrical Characterization of the (La,Ca) (Cr,Co)O3 System," Solid State Ionics, vol. 78, no. 3 thru 4, pp. 235 - 243, Elsevier, Jan 1995.
The definitive version is available at https://doi.org/10.1016/0167-2738(95)00096-O
Department(s)
Materials Science and Engineering
Second Department
Physics
Keywords and Phrases
Cobaltites; Disproportionation; Electrical conductivity; Seebeck coefficient; Trapping
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 1995
Comments
U.S. Department of Energy, Grant None