| Sumario: | Bi2Sr2-xBaxCo2Oy polycrystalline samples (0.00 = × =0.15) were prepared through the classical solid-state reaction method. It has been found that Ba-doped Bi2Sr2Co2Oy was obtained as major phase in all samples, based on XRD results. On the other hand, SEM studies have shown the presence of small amounts of secondary phases. The electrical resistivity values of all Ba doped samples decreased when compared to the undoped one, being minimum for the 0.075Ba doped ones. Seebeck coefficient increase with the increasing temperature in all samples, reaching the highest values in the 0.025 Ba doped sample. Finally, power factor has been calculated using the Seebeck coefficient and electrical resistivity values to determine the thermoelectric performances of samples. The maximum PF value of 0.14 mW/K2 m at 650 °C was obtained for 0.075Ba doped sample, which is around 25% higher than the undoped sample at the same temperature. All these results clearly show that the thermoelectric properties of the Bi2Sr2Co2Oy system can be improved by Ba doping at optimal values. © 2022 Elsevier B.V.
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