Preparation and Characterization of Novel Thermoelectric Material of Ca_3Co_4O_9

Ca3Co4O9 is a novel kind of material with mid and high temperature thermoelectric properties. The samples of Ca3Co4O9were synthesized by the sol-gel method,and the structures were characterized by XRD,SEM,TG-DTA and IR spectrum. The thermoelectric properties of Ca3Co4O9,such as Seebeck coefficient,electrical conductivity and power factor were studied especially. The results show that,the XRD spectrum of Ca3Co4O9 was in accordance with the JCPDS card of standard,and no impurities were found. Because of the high purity and fine structure,the influence factors of car-rier mobility decrease. Thus,the samples have high Seebeck coefficient ,electrical conductivity,high power factor.