Keywords: magnetic, nanoparticles, spinel, microemulsion, nanotechnology
Magnetic spinel ferrite nanoparticles from microemulsions
Microemulsion methods have been used to prepare a wide range of spinel ferrite nanoparticles with low size distribution. Synthesis conditions are summarised for both normal micelle (o/w) and reverse micelle (w/o) synthesis procedures with examples over a variety of ferrite nanoparticles (MFe2O4; M = Co, Fe, Mg, Mn, Cr, Zn). Size selection through control over metal cation concentration and reaction temperature using normal micelle methods as well as through adjusting the water pool diameter in reverse micelle methods is discussed. The ferrite nanoparticles display superparamagnetic properties and the size-dependent magnetization results are consistent with Stoner-Wohlfarth theory for single domain particles. SQUID magnetometry and Mössbauer spectroscopy results are presented.