Polycrystalline samples of Ca3-xEuxCo 3.95Ga0.05O9+δ (x = 0.00, 0.02 and 0.10) have been prepared by conventional solid-state synthesis and their thermoelectric properties measured at 25 K to 300 K. The XRD results revealed that all the samples are single phase. The thermopower of all the samples was positive, indicating that the predominant carriers are holes over the entire temperature range. The electrical resistivity and thermopower were simultaneously increased with increasing Eu3+ content. The total thermal conductivity decreased with increasing Eu3+ content. A maximum dimensionless figure of merit of 0.033 at 300 K was reached for Ca 2.9Eu0.1Co3.95Ga0.05O 9+δ, which is about 27 % higher than that of the undoped sample. These results suggest that the Eu is an effective doping element for improving the thermoelectric properties of Ca3Co 3.95Ga0.05O9+δ.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering
- Materials Chemistry