An optimal low-temperature tartrate precursor method for the synthesis of monophasic nanosized ZnFe2O4

Abstract

In this study, the synthesis of monophasic nanocrystalline zinc ferrite (ZnFe2O4) was achieved by controlling the thermal decomposition conditions of a zinc–iron tartrate precursor method. Differential thermal analysis/thermogravimetry (DTA/TG), X-ray diffraction (XRD), Fe2+ content analysis, transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) techniques were used to investigate the effect of heat treatment conditions on the calcined powders. The thermal decomposition of the precursor led to an intermediate phase formation of ZnO, Fe3O4, and γ-Fe2O3. It was found that the Fe3O4 → γ-Fe2O3 oxidation reaction is the key step in producing monophasic nanosized ZnFe2O4. The monophasic nanoparticles of ZnFe2O4 can be obtained when the precursor is heat treated under a low temperature (300–400 °C) and long residence time (4 h) process that can prompt the Fe3O4 oxidation and prevent the formation of α-Fe2O3.