Synthesis and Characterization of Ca_2.7-xAg_0.3Eu_xCo₄O₉ Semiconducting Materials for Thermoelectric Generators

In the area of thermoelectric implementation, the development of thermoelectric materials takes a crucial role, especially in areas with substantial thermal differentials, aiming to convert these differentials into electrical signals. This study systematically describes the production and characterization of Ca2.7-xAg0.3EuxCo4O9 materials for use in thermoelectric applications, necessitating robust systems capable of harnessing temperature differences for power generation. These ceramics are synthesized using the sol-gel technique using precursor materials. After the gelation process, the obtained xerogel was desiccated and calcined to acquire the final Ca2.7-xAg0.3EuxCo4O9 bulk materials. Comprehensive characterization, encompassing thermal, structural, microstructural, and thermoelectric characteristics, is performed with methods such as XRD, DTA-TG, XPS, FTIR, SEM, and thermoelectric measuring instruments. XRD and XPS results confirmed the crystalline nature of the synthesized Ca2.7-xAg0.3EuxCo4O9 ceramic powders and verified the inscription of Eu and Ag dopants into Ca3Co4O9 ceramic powder materials, illustrating the successful fabrication of p-type thermoelectric materials. Thermoelectric results showed that electrical resistivity and the Seebeck coefficient were measured as 9.39 m Omega cm, and 242.15 mu V/K respectively, which yields a maximum power factor of 0.62 smW/mK2 at 800 degrees C. According to these results, the study determines that the manufactured semiconducting ceramic materials illustrate high performance for high-performance thermoelectric generator fabricating.