Low temperature synthesis of calcium cobaltites in a solid state reaction

• DOI: 10.1007/s10832-007-9069-7
• Publication Date: 2007-03-05T16:42:38Z
• Authors: Paweł Smaczyński; Małgorzata Sopick...; Karolina Kozłowska; Julian Plewa
• Keywords: Stoichiometry

This paper presents synthesis of calcium cobaltites of the nominal composition of Ca3Co4O9 prepared by the solid state reaction. The reaction between CaCO3 and Co3O4 was investigated at 700–900 °C during 20 h and at 800 °C during 2–30 h. Mass changes, phase composition and Co+3, Co+4 content were examined. Stability of the calcined specimens was tested by DTA/TG. It was found that two phases: Ca3Co4O9 and Ca3Co2O6 were present as a result of calcinations above 800 °C. On the other hand, the temperature of 750 °C was too low for calcium cobaltites to be synthesized. Mono-phase material with Ca3Co4O9 phase was obtained after calcinations at 800 °C but non-stoichiometry of the compound and its relation to the calcinations time were found. Once synthesized, the compound was stable up to 900 °C.