Single Source Precursor Approach for the Sol−Gel Synthesis of Nanocrystalline ZnFe₂O₄ and Zinc−Iron Oxide Composites

Abstract

Nanostructured ZnFe2O4 and zinc oxide−iron oxide composites were obtained by sol−gel processing of a hetero-bimetallic alkoxide. For this purpose the novel molecular precursors Fe2Zn(OR)8 (R = tBu, iPr), fully characterized by spectroscopic and single-crystal diffraction techniques, have been synthesized and their applications in the sol−gel procedure were investigated. The obtained xerogels were annealed at very low temperatures (down to 200 °C) yielding crystalline phases with very small crystallite grain sizes. The phase compositions of the material strongly depend on the polarity of the solvents used in the hydrolysis reaction. When the hydrolysis was performed in the polar propan-2-ol, the spinel ZnFe2O4 (franklinite) formed at annealing temperature of 200 °C with a mean crystallite grain size Dvol of 2.24 nm. However, when using the less polar toluene as solvent in the sol−gel process, iron oxide and zinc oxide are formed together with the franklinite phase. This mixture of phases transforms to the spinel as unique crystalline phase with increasing sintering temperature.

One-pot low temperature synthesis of MFe2O4 (M=Co, Ni, Zn) superparamagnetic nanocrystals

“…Most importantly, it is necessary to find an economical and efficient process for the synthesis of ferrite nanocrystals. However, the ferrite nanocrystals are difficult to obtain via using cheap and multiple reactants under moderate conditions [13]. High calcination temperature is always needed to form the MFe 2 O 4 spinel structure, which results in large particles and a broad size distribution.…”

Effects of annealing temperature on the magnetic properties of ZnFe1.97Eu0.03O4 nanoparticles

“…3. The peaks at 1134.5 and 1163.6 eV corresponded to Eu3d 5/2 and Eu3d 3/2 , respectively [30], which indicated that the Eu ion owns ?3 valence in ZnFe 1.97 Eu 0.03 O 4 nanoparticles [31].…”

Fabrication and Characterization of ZnFe₂O₄ Thin Film Based Metal-Insulator-Semiconductor Capacitors

“…Plocek et al [12] reported the preparation of ZnFe 2 O 4 /SiO 2 nano-composites by the sol-gel method. Veith et al [13] studied the synthesis of nano-crystalline ZnFe 2 O 4 and zinc-iron oxide composites by the sol-gel method. Li et al [14] reported the optical and structural properties of TiO 2 -ZnFe 2 O 4 composite film prepared by r.f.…”