Evolution of intermediate phases in the synthesis of zinc ferrite nanopowders prepared by the tartrate precursor method

The advanced electronic applications of zinc ferrite (ZnFe2O4) material are considered to require improvement in the powder processing, particularly, meticulous particle control in the nanometer range, stoichiometry and phase purity. This article presents the process of zinc ferrite formation from tartrate precursors, emphasizing the intermediate phase evolution during the thermal treatment. The variation of the intermediate phases, crystallite size and chemical composition of the products at different calcination temperatures have been investigated by X-ray diffraction (XRD), Fe2+ content analysis, transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS) techniques. Results show that the stoichiometry and phase purity of the resultant zinc ferrite nanopowders has been noted to be highly influenced by their intermediate phases. Finally, the formation mechanism of zinc ferrite is discussed. A single phase, approaching the desirable stoichiometric zinc ferrite nanoparticles, is noted to be possibly prepared produced by an annealing treatment of the precursor gel powders at 350 °C for 4 h.