Mössbauer studies on the thermolysis of manganese tris(malonato)ferrate(III)hexahydrate

Summary

The thermal decomposition of manganese tris(malonato)ferrate(III) hexahydrate, Mn₃[Fe(CH₂C₂O₄)₃]₂ ^. 6H₂O has been investigated from ambient temperature to 600 °C in static air atmosphere using various physico-chemical techniques, i.e., simultaneous TG-DTG-DSC, XRD, Mössbauer and IR spectroscopic techniques. Nano-particles of manganese ferrite, MnFe₂O₄, have been obtained as a result of solid-state reaction between a-Fe₂O₃ and MnO (intermediate species formed during thermolysis) at a temperature much lower than that for ceramic method. SEM analysis of final thermolysis product reveals the formation of monodisperse manganese ferrite nanoparticles with an average particle size of 35 nm. Magnetic studies show that these particles have a saturation magnetization of 1861G and Curie temperature of 300 °C. Lower magnitude of these parameters as compared to the bulk values is attributed to their smaller particle size.