Calcium ferrite formation from the thermolysis of calcium tris (maleato) ferrate(III)

For preparing calcium ferrite, calcium tris (maleato) ferrate(III) precurso r was prepared by mixing aqueous solutions of iron(III) maleate, calcium ma leate and maleic acid. Various physico-chemical techniques i.e. TG, DTG, DT A, Mossbauer, XRD, IR etc have been used to study the decomposition behavio ur from ambient to 900 degrees C and ferrite formation. Three consecutive d ecomposition steps leading to the formation of alpha-Fe2O3 and calcium carb onate have been observed at various stages of thermolysis. In the final sta ge the ferrite, Ca2Fe2O5, is obtained as a result of solid state reaction b etween alpha-Fe2O3 and calcium carbonate at 788 degrees C, a temperature mu ch lower than for ceramic method. The results have been compared with those of the oxalate precursor.