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 ...
Single phase, orthohombic structured Ca0.98Bi0.02Mn1−xSixO3−delta (x = 0.00, 0.02 and 0.03) samples were prepared using solid state reaction. The authors investigated whether they could improve the thermoelectric properties of the product by substituting calcium and manganese with bismuth and silicon, respectively. The resulting products had an increase in electrical resistivity and thermopower and a decrease in thermal conductivity as the amount of silicon added increased. Magnetic moments decreased in the ...
The effects of the substitution of Ca with Gd in the Ca1-xGdxMnO3-delta system were investigated. It was determined that the partial substitution of Gd resulted in decreased resistivity and increased thermal conductivity. The change in these properties was attributed to electronic effects....
The thermoelectric and magnetic properties of the Ca3Co4-xCuxO9+delta system where x = 0, 0.05, 0.07, 0.10, and 0.15 were investigated as materials of this type have potential for use in thermoelectric generators. The goal of this work was to identify the sample in this system having the highest thermoelectric figure of merit. To accomplish this, a high thermopower, a high thermal voltage, a low resistivity, and a low thermal conductivity were required. It ...
Two series of co-doped mifit-layered cobaltites were prepared with compositions of Ca3-xYbxCo4-yAgyO9+delta and Ca3-xEuxCo4-yAgyO9+delta. All of the samples exhibited an increasing thermopower as temperature was increased up to a temperature of 700 K. The sample with the highest power factor and figure of merit was Ca2.95Eu0.05Co3.95Ag0.05O9+delta....
