A Moessbauer study of the reaction between barium carbonate and iron(III) oxide

An investigation of the kinetics of the formation of barium monoferrite (BaFe2O4) and of barium hexaferrite (BaFe12O19) by means of 57Fe Moessbauer spectroscopy is reported. Two mixtures of BaCO3:α-Fe2O3 were prepared according to the mole ratio 1:1 and 1:6 and annealed at different temperatures in the range of 700 to 1200 0C. The Moessbauer spectra of the reaction products and the quantities of the different iron-containing phases in the samples determined from computer-fitted spectra are given. Results indicate that the reaction starts with simultaneous formation of mono- and hexaferrite in both cases of initial mixture