Abstract: Ca3Co4O9 ceramics were prepared by a Sol-gel method using hydrous calcium and cobalt nitrate as raw materials and citric acid as complexing agent. The phase composition, atomic composition and microstructure of Ca3Co4O9 ceramics were investigated by X-ray diffraction (XRD),energy-dispersive X-ray analysis (EDX) and scanning electron microscope (SEM), respectively. The results show that Ca3Co4O9 single phase can be fabricated at 800～900 ℃. Ca3Co4O9 ceramics contain randomly-oriented plate-shaped grains with layered structure. All the sample are not dense enough and the porosities are relatively large.

Key words: thermoelectric materials%Ca3Co4O9 ceramics%Sol-gel method