Polycrystalline samples of Ca3-x Ag x Co 3.95Fe0.05O9+δ (x = 0.0, 0.1, 0.2, and 0.3) have been prepared by conventional solid-state synthesis. The x-ray diffraction patterns reveal that all the samples are single phase. The thermopower of all the samples is positive, indicating that the predominant carriers are holes over the entire temperature range. The electrical resistivity and thermopower simultaneously decrease with increasing Ag content. The highest power factor (2.66 μW cm-1 K-2 at 150 K) is reached for the Ca2.8Ag0.2Co3.95Fe0.05O 9+δ, representing an improvement of about 16 % compared to the undoped sample. These results suggest that the Ag is an effective doping element for enhancing the thermoelectric properties of Ca3Co 3.95Fe0.05O9+δ.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry