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Abstract: Nanostructured NiZn ferrites were synthesized using two different techniques: first, a precipitation procedure in the reverse micelles of a CTAB/1-hexanol/H2O microemulsion, and second, precipitation in a bulk aqueous solution. XRD measurements, magnetic measurements, TEM imaging, analytical measurements and thermal analyses were used in an attempt to reveal the chemical pathway that leads to the formation of NiZn ferrite in the microemulsion and in the bulk aqueous solution. It was found that reverse micelles do not act as inert nano-sized reactors that influence only morphological properties of the synthesized powders, but have a decisive influence on the identity of the final product when compared to the non-microemulsion procedure, and therefore present the molecular structures which are actively engaged in the chemical pathway according to which the herein presented room temperature synthesis of NiZn ferrite nanoparticles takes place. The influence of the initial pH on the chemical pathway of reverse-micellar synthesis and the morphology of the synthesized particles was discussed after initially it was found that the pH of the precipitation ought to be higher than 8 in order to obtain the desired ferrite as a final product. [Copyright &y& Elsevier]

Abstract: Stoichiometric nanocrystalline nickel–zinc ferrites were synthesized by a reverse micelle method following a multi-microemulsion approach. Different pH values were chosen for the alkali precipitating reaction during the synthesis of different powders. Synthesized, as-dried and subsequently calcined powders were characterized in terms of their magnetic properties. XRD analyses and specific-surface area measurements were used to determine the average particle sizes of the synthesized samples. DCS and TGA measurements were performed to reveal the phase transitions within the samples at elevated temperatures, whereas TEM was used to view and record the microstructure of the nanosized ferrite samples. A possible mechanism of the formation of the synthesized NiZn-ferrite was also discussed. [Copyright &y& Elsevier]