Study of manganese ferrite powders prepared by a soft mechanochemical route

Manganese ferrite, MnFe2O4 have been prepared by a soft mechanochemical route from mixture of (a) Mn(OH)2 and α-Fe2O3 and (b) Mn(OH)2 and Fe(OH)3 powders in a planetary ball mill. The mixture was activated for varying duration. Soft mechanochemical reaction leading to formation of the MnFe2O4 spinel phase was followed by X-ray diffraction, Raman spectroscopy, scanning and transmission microscopy and magnetization measurements. The spinel phase formation was first observed after 12 h of milling and its formation was completed after 25 h in both cases. The synthesized MnFe2O4 ferrite has a nanocrystalline structure with a crystallite size of about 40 and 50 nm respectively for cases (a) and (b). There are five Raman active modes. Measurements after 25 h of milling show magnetization values of 70.4 emu/g and 71.1 emu/g respectively for cases (a) and (b). In order to understand better the whole process of phase formation, Mössbauer measurements were done.

► In this paper MnFe2O4 has been prepared by a soft mechanochemical synthesis in a planetary ball mill. ► The spinel phase was first observed for 12 h and completed for 25 h of milling in both case of synthesis. ► On the basis of Raman research is observed five first-order Raman active modes. ► Magnetic measurements after 25 h of milling show magnetization value of 70.4 emu/g and 71.1 emu/g. ► Mössbauer spectrometry reveals superparamagnetic particles.