Bi掺杂的Ca3Co4O9的微结构和电输运性能

摘要

Bi doped Ca3Co4O9 thermoelectric materials were prepared by solid state reaction. The phase and morphology of the samples were investigated by XRD and SEM. The conductivity of Bi doped Ca3Co4O9 ceramics were investigated with four-wire conductivity measurement. The results show that all the Ca3-xBixCo4O9 samples are single phase of Ca3Co4O9. The grains are in lamellar structure observed by SEM. With Bi doping content increase, average grain size and the relative density can be increase greatly and the conductivity can also be improve, which are related to the relative density, the growth with preferred orientation and average grain sizes.%采用固相反应法制备了Bi掺杂的Ca3Co4O9热电材料.利用XRD和SEM等方法表征了样品的物相和微观组织.利用四线法测量了所有样品的电导率.研究结果表明:Bi掺杂的样品具有Ca3 Co4O9单相,晶粒呈片状结构；随着Bi掺杂浓度的增加,样品的平均晶粒大小和致密度增加,电导率增大；电导率增加与样品的致密度,择优生长,晶粒大小密切相关.