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 ...
The partial replacement of Ca2+ ions with Eu3+ in the Ca3Co3.95Ga0.05O9+delta system to give polycrystalline samples of Ca3-xEuxCo4O9+delta (x = 0.00, 0.05, 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 when Eu3+ is added, and the thermal conductivity decreased. The highest thermoelectric figure of merit ...
A paraffin-based composite phase change material (PCM) was prepared by the addition of hexagonal boron nitride (h-BN) nanosheets to melted paraffin wax followed by vigorous stirring. The nanosheets were added in quantities ranging from 1 to 10 wt. %. A reference sample of pure paraffin was also prepared. It was determined that the addition of h-BN nanosheets resulted in an increase in thermal conductivity and that the melting and solidification rates were also ...
