Fabrication of p-type synthesis of p-type Ca2.7 Ag0.3 Co4O9 semiconducting materials for thermoelectric generators in aerospace applications

In aviation applications, thermoelectric materials play a crucial role in harnessing substantial thermal differentials to generate electrical signals. This study emphasizes the use of thermoelectric modules in fixed-wing aircraft and satellites, where robust systems are essential for effective power generation. The paper details the production and characterization of Ca2.7Ag0.3Co4O9 ceramics for aerospace thermoelectric applications. Using a sol-gel method with Ca, Ag, and Co precursors, homogeneous solutions were prepared, mixed, and stirred at 100 degrees C, with citric acid monohydrate added as a chelating agent. The xerogel formed was dried at 200 degrees C, calcined at 800 degrees C, and sintered at 900 degrees C for 24 h in air, yielding the final material. Extensive characterization using TG-DTA, FTIR, XRD, XPS, SEM, and thermoelectric measurement machines confirmed that the produced semiconducting ceramics are suitable for thermoelectric generator production. The synthesis of Ca2.7Ag0.3Co4O9 ceramic powders involved solution preparation (pH 1.51, turbidity 8.33 ntu), drying at 100 degrees C, combustion at 200 degrees C, calcination at 800 degrees C, and sintering at 900 degrees C. FTIR analysis confirmed the breakdown of O-H, N-O, and C-N bonds at 800 degrees C, forming the desired phase. XRD confirmed the crystalline nature and structural impact of Ag doping. XPS detected Ag, confirming p-type semiconductor synthesis. SEM revealed expected grain morphologies. Thermoelectric measurements at 800 degrees C showed a Seebeck coefficient of 208.40 mu V/K, electrical resistivity of 14.59 m Omega cm, and a power factor of 0.50 mW/m & sdot;K2. Furthermore, the low density and chemical stability of this oxide-based material offer additional advantages for lightweight, durable, and environmentally friendly applications in aerospace thermoelectric systems.