Room temperature ferromagnetic ordering in indium substituted nano-nickel-zinc ferrite

Nano-nickel-zinc-indium ferrite (NZIFO)(Ni0.58Zn0.42InxFe2-xO4) with varied quantities of indium (x=0, 0.1, 0.2) have been synthesized via reverse micelle technique. X-ray diffraction and transmission electron microscopy confirmed the size, structure, and morphology of the nanoferrites. The addition of indium in nickel-zinc ferrite (NZFO) has been shown to play a crucial role in enhancing the magnetic properties. Room temperature Mossbauer spectra revealed that the nano-NZFO ferrite exhibit collective magnetic excitations, while indium doped NZFO samples have the ferromagnetic phase. The dependence of Mossbauer parameters, viz. isomer shift, quadrupole splitting, linewidth, and hyperfine magnetic field, on In3+ concentration has been studied. Mossbauer study on these nanosystems shows that the cation distribution not only depends on the particle size but also on the preparation route. Mossbauer results are also supported by magnetization data. Well defined sextets and appearance of hysteresis at room temperature indicate the existence of ferromagnetic couplings which makes nano-NZIFO ferrite suitable for magnetic storage data. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3062956]