Abstract
Misfit-layered oxides Ca3-xLnxCo4O 9+δ with Ln = Dy, Er, Ho, and Lu were synthesized using solid state reactions. The resulting samples were hot-pressed (HP) at 1123 K in air for 2 h under a uniaxial pressure of 60 MPa. Thermoelectric properties of Ca3-xLnxCo4O9+δ were investigated up to 1200 K. Both the Seebeck coefficient and electrical resistivity increase upon Ln substitution for Ca. Among the Ln-doped samples, the magnitude of Seebeck coefficient tends to increase with decreasing ionic radius of Ln3+. The Ln-doped samples exhibit a lower thermal conductivity than the non-doped one due to a decrease of their lattice thermal conductivity. The dimensionless figure of merit, ZT, reaches 0.36 at 1073 K for the Ca2.8Lu0.2Co4O9+δ sample, which is about 1.6 times larger than that for the non-doped counterpart.
Original language | English |
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Pages (from-to) | 977-981 |
Number of pages | 5 |
Journal | Journal of Alloys and Compounds |
Volume | 509 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jan 21 2011 |
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry