Effect of the Preparation Method on the Structure and Properties of the Layered Calcium Cobaltate

Irina V. Matsukevich, Andrey I. Klyndyuk
Page no. 73-84

By means of colorimetry, turbidimetry, thermogravimetry, differential thermal analysis, X-ray analysis and IR absorption spectroscopy the processes taking place at preparation of Ca₃Co₄O_9+d ceramics using solid-state reactions, citrate, polymeric and sol-gel methods were studied. The crystal structure and microstructure, thermal stability, thermal expansion, thermal conductivity, electrical conductivity and thermo-EMF of the samples were investigated and values of their power factor and figure-of-merit were calculated. It is shown that usage of solution methods let us obtain more dense and fine-grained ceramics, which characterizes more higher values of electrical conductivity and power factor.

Keywords: Layered calcium cobaltate, preparation method, oxide thermoelectric, thermal stability, power factor.