Synthesis and magnetic properties of Co1-xZnxFe2O4 (x=0 ÷ 1) nanopowders by thermal decomposition of Co(II), Zn(II) and Fe(III) carboxylates

Nanoparticles of cobalt-zinc ferrite Co1-xZnxFe2O4 with x varying from 0 to 1.0 were prepared by a new method, the thermal decomposition of carboxylates of Fe(III), Co(II) and Zn(II). The obtained carboxylate precursor was characterized by thermal analysis and FT-IR spectroscopy. The precursor was annealed at 350, 600 and 1000 degrees C. It was found that the spinet cobalt-zinc ferrite was formed starting at 350 degrees C, but in mixture with simple oxides gamma-Fe2O3, Co3O4 and ZnO. At 1000 degrees C Co1-xZnxFe2O4 was formed quantitatively as a single, well-crystallized phase. The saturation magnetization of the samples annealed at 1000 degrees C decreased significantly with increasing Zn2+ content from 83.93 emu/g (x=0) to 4.92 emu/g (x=1.0). At 350 and 600 degrees C the saturation magnetization had the same trend, even if there were contributions of other magnetic phases. Obtaining of spinel ferrite was evidenced by X-ray diffractometry and FT-IR spectrometry. Powder morphology was determined by scanning electron microscopy. Magnetic properties of the synthesized ferrites were investigated employing a conventional induction method. (C) 2015 Elsevier B.V. All rights reserved.