Ca_3Co_4O_(9+δ)与Ca_2Co_2O_5的制备与电学性能研究

Preparation and Study on Electrical Properties of Ca_3Co_4O_(9+δ) and Ca_2Co_2O_5

采用溶胶-凝胶与热压烧结相结合的方法制备了Ca3Co4O9+δ和Ca2Co2O5热电材料.X射线衍射(XRD)测试结果表明,两种材料均沿c轴有择优生长趋势.从样品的扫描电子显微照片(SEM)来看,两种材料已烧结,基本达到致密的程度.在室温至1073 K温区,测试了样品的电导率和Seebeck系数.结果表明,两种材料电输运性能均随温度升高而增加,Ca3Co4O9+δ样品的电导率、Seebeck系数和功率因子明显高于Ca2Co2O5.

Ca3Co4O9＋6andCa2Co2O5 were prepared by a combined process of sol - gel and hot - pressing. X -ray diffraction （XRD） analysis indicates that the both kinds of materials grow along c -axis. As shown in SEM images, the materials are all sintered and density. The electrical conductivity and Seebeck coefficient are measured from room - temperature to 1273 K. The electrical transport properties of the both materials increase with the temperature, while, the electrical conductivity, Seebeck coefficient and power factor of Ca3Co4O9＋8 sample is higher than those of Ca2Co2O5 sample.