A mechanism for the formation of nanostructured NiZn ferrites via a microemulsion-assisted precipitation method

Abstract

Nanostructured NiZn ferrites were synthesized using two different techniques: first, a precipitation procedure in the reverse micelles of a CTAB/1-hexanol/H 2O 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.