文摘
Ca3Co4O9+未 samples were synthesized by solid-state (SS) and sol鈥揼el (SG) reactions, followed by spark plasma sintering under different processing conditions. The synthesis process was optimized and the resulting materials characterized with respect to their microstructure, bulk density, and thermoelectric transport properties. High power factors of about 400聽渭W/m路K2 and 465聽渭W/m路K2 (at 800掳C) were measured for SS and SG samples, respectively. The improved thermoelectric performance of the SG sample is believed to originate from the smaller particle sizes and better grain alignment. The SG method is suggested to be a beneficial means of obtaining high-performance thermoelectric materials of Ca3Co4O9+未 type.