Abstract
Phase equilibria, crystal structure, and transport properties in the (100-x) La0.95Ni0.6Fe0.4O3xCeO 2 (LNFCx) system (x=275 mol%) were studied in air. Evolution of phase compositions and crystal structure of components was observed. The LNFCx (2≤x≤10) are three-phase and comprise the perovskite phase with rhombohedral symmetry (R3c), the modified ceria with fluorite structure (Fm3m), and NiO as a secondary phase. These multiphase compositions exhibit metallic-like conductivity above 300 °C. Their conductivity gradually decreases from 395.6 to 260.6 S/cm, whereas the activation energy remains the same (Ea=0.040.05 eV), implying the decrease in the concentration of charge carriers. Phase compositions in the LNFCx (25≤x≤75) are more complicated. A change from semiconducting to metallic-like conductivity behavior was observed in LNFC25 at about 550 °C. The conductivity of LNFCx (25≤x≤75) could be explained in terms of a modified simple mixture model.
Original language | English |
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Pages (from-to) | 1499-1504 |
Number of pages | 6 |
Journal | Journal of Solid State Chemistry |
Volume | 184 |
Issue number | 6 |
DOIs | |
Publication status | Published - Jun 2011 |
Externally published | Yes |
Keywords
- CeO
- Conductivity
- Perovskite
- Phase equilibria
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry