Study of the thermal decomposition of iron and barium citrates

Iron citrate decomposes to give α-Fe2O3 as an end product at 460°C via a four-step process. Barium citrate has been found to decompose to a stable barium carbonate at 412°C. It is, however, observed that a mixture of iron and barium citrates decomposes to BaO and either γ-Fe2O3 or Fe3O4 or a mixture of these two oxides. Thus, the mixture does not decompose to give α-Fe2O3 and BaCO3 as obtained in the individual decomposition of iron citrate and barium citrate, respectively. The iron and barium oxides obtained as a result of decomposition of the mixture then chemically combine to form barium ferrite at 600°C.