Concerning the cation distribution in MnFe2O4 synthesized through the thermal decomposition of oxalates Original Research Article

A single phase manganese ferrite powder have been synthesized through the thermal decomposition reaction of MnC2O4·2H2O–FeC2O4·2H2O (1:2 mole ratio) mixture in air. DTA-TG, XRD, Mössbauer spectroscopy, FT-IR and SEM techniques were used to investigate the effect of calcination temperature on the mixture. Firing of the mixture in the range 300–500 °C produce ultra-fine particles of α-Fe2O3 having paramagnetic properties. XRD, Mössbauer spectroscopy as well as SEM experiments showed the progressive increase in the particle size of α-Fe2O3 up to 500 °C. DTA study reveals an exothermic phase transition at 550 °C attributed to the formation of a Fe2O3–Mn2O3 solid solution which persists to appear up to 1000 °C. At 1100 °C, the single phase MnFe2O4 with a cubic structure predominated. The Mössbauer effect spectrum of the produced ferrite exhibits normal Zeeman split sextets due to Fe3+ions at tetrahedral (A) and octahedral (B) sites. The obtained cation distribution from Mössbauer spectroscopy is (Fe0.92Mn0.08)[Fe1.08Mn0.92]O4.