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

A single phase manganese ferrite powder have been synthesized through the thermal decomposition reaction of MnC2O4.2H(2)O-FeC2O4.2H(2)O (1:2 mole ratio) mixture in air. DTA-TG, XRD, Mossbauer 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 degreesC produce ultra-fine particles of alpha-Fe2O3 having paramagnetic properties. XRD, Mossbauer spectroscopy as well as SEM experiments showed the progressive increase in the particle size of alpha-Fe2O3 up to 500 degreesC. DTA study reveals an exothermic phase transition at 550 degreesC attributed to the formation of a Fe2O3-Mn2O3 solid solution which persists to appear up to 1000 degreesC. At 1100 degreesC, the single phase MnFe2O4 with a cubic structure predominated. The Mossbauer effect spectrum of the produced ferrite exhibits normal Zeeman split sextets due to Fe(3+)ions at tetrahedral (A) and octahedral (B) sites. The obtained cation distribution from Mossbauer spectroscopy is (Fe0.92Mn0.08)[Fe1.08Mn0.92]O-4. (C) 2003 Elsevier Ltd. All rights reserved.