Effects of Various Sintering Conditions on the Structural and Magnetic Properties of Zinc Ferrite (ZnFe₂O₄)

Abstract

Zinc ferrite (ZnFe₂O₄) nanoparticles have attracted the attention of researchers because of their unique chemical properties and particle-size-dependent magnetic properties. High-surface-area spinel ferrites have numerous technical applications in areas such as high-density information storage, ferrofluids, and catalysis. The coprecipitation technique is the preferred method for preparing nanoscale ZnFe₂O₄ because it results in a small crystals with a uniform size distribution. In this study, the synthesis was conducted in solution for 48 h, followed by sintering at 1000°C for 1.5–3.5 h. The smallest crystals (70.58 nm) were found in the sample sintered for 2.5 h. Fourier transform infrared spectroscopy (FTIR) functional-group analysis confirmed the presence of Fe–O and Zn–O bonds of cations in octahedral and tetrahedral sites. The ZnFe₂O₄ sintered for 3.5 h was superparamagnetic. The characterization results suggest that the obtained ZnFe₂O₄ could be used as a nanofluid in heat exchangers.

Keywords:
Ferrite; Coprecipitation; Hysteresis; Sintering