Influence of processing methodology on the structural and magnetic behavior of MgFe2O4 nanopowders

Three different wet chemistry routes namely reverse micelle, citrate gel and co-precipitation methods were used to synthesize magnesium ferrite nanopowders. The synthesized spinel was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman spectroscopy techniques, transmission electron microscopy (TEM) and Superconducting Quantum Interference Device magnetometry (SQUID). The gel combustion method yield comparatively pure crystalline phase of MgFe2O4 and relatively higher saturation magnetization of 22.7 emu/g. The material synthesized using co-precipitation method yield other phases in addition to the targeted phase. The average diameter of nanoparticles obtained from reverse microemulsion route was about 19.6 +/- 2 nm, and for those obtained from gel combustion and co-precipitation route are highly agglomerated. The reverse micelle process produces fine nanosized particles compared with other methods reported in the literature. Superconducting Quantum Interference Device (SQUID) magnetometer reveals that the ferrite nanopowders obtained from the reverse micelle, gel combustion and co-precipitation route exhibit superparamagnetism. The selection of MgFe2O4 synthesis method largely depends on the targeted applications and desired properties. The results reported in this study are useful for establishing a simple method for the preparation of MgFe2O4 nanopowders. (C) 2011 Elsevier B. V. All rights reserved.