The thermoelectric properties of Ca3-xYbxCo3.95Ga0.05O9+delta where x = 0.00, 0.02, 0.05, and 0.10 were determined at temperatures less than 300 K. It was determined that the partial substitution of Yb3+ for Ca2+ resulted in an increase in resistivity and thermopower. The thermal conductivity was found to decrease with increasing Yb3+ content, and the sample producing the highest thermoelectric figure of merit at 300 K was the x = 0.05 sample....
The thermoelectric properties of the co-doped misfit-layered cobaltites of Ca3-xAgxCo3.95Fe0.05O9+delta (x=0.0, 0.1, 0.2, 0.3) were investigated at temperatures between 300 and 700 K. It was found that the thermopower increased with increasing temperature. The thermal conductivity was found to increase with increasing Ag+ content in the samples, and the highest calculated figure of merit was determined for the Ca2.8Ag0.2Co3.95Fe0.05O9+delta....
The thermoelectric properties of the Ca1-xGdxMnO3-delta system where x= 0.00, 0.02, and 0.05 were evaluated. It was determined that the sample with the lowest electrical resistivity was the Ca0.95Gd0.05MnO3-delta sample. This result was attributed to the increase content of Mn3+ in the Mn4+ matrix resulting from doping of gadolinium. The dominant charge carriers in all samples were holes, as the thermopower was negative. The highest thermoelectric figure of ...
Bi2-xSbxTe3 thermoelectric materials, where x = 1.52 and 1.55 were prepared and evaluated for their thermoelectric properties. Three samples in total were prepared, two with x = 1.52 and 1.55 were synthesized at 140oC and one with x = 1.55 was synthesized at 160 oC. It was determined that the two samples synthesized at the higher temperature had lower resistivity than that which was synthesized at higher temperature. The figure of merit for the sample synthesized at 140oC, ...
The partial replacement of Ca2+ ions with Eu3+ in the Ca3Co3.95Ga0.05O9+delta system to give polycrystalline samples of Ca3-xEuxCo3.95Ga0.05O9+delta (x = 0.00, 0.02, and 0.10) was performed in order to assess the effect that the dopant had on thermoelectric properties of this system. It was found that the electrical resistivity and thermopower increased with increasing Eu3+ content, and the thermal conductivity decreased. The highest thermoelectric figure of ...
