Iron oxide nanoparticles can be synthesized by sol-gel technique [1] in aqueous media or in organic solvents. It was obtained that the nanoparticles’ properties strong depend on their surface characteristics. The aim of a present report was to investigate influence of heat treatment of the iron oxides nanoparticles aqueous solutions on their structure and physical properties.
Magnetite Fe₃O₄ nanoparticles were synthesized by co-precipitation from 0,01 M Fe²⁺ and 0,02 M Fe³⁺ solutions, added to ammonium hydroxide and stabilized by oleic acid. The obtained solutions were heated in 50-100^oC range during 1 -10 h.
It was shown that the nanoparticles of magemite and magnetite can be obtained by this method varying amount of the precursors. Increasing amount of stabilizer, leads to decreasing of magnetic susceptibility of the nanoparticles. Prolonged heat treatment result in the nanoparticles growth and forming of spherical agregates with size about 40-50 nm. The TEM analysis showed that iron oxide nanoparticles sizes can be regulated in 5-50 nm range by the amount of stabilizer. Magnetic properties of obtained solutions were investigated by the depth of solution meniscus in electromagnetic field. Peaks, at 1050 nm, were observed in the infrared absorption spectra of magnetite due charge transfer transitions Fe²⁺- ^Fe3+ are in agreement with [2], where synthesis based on the decomposition of presynthesized iron oleate was used.

References

1. Berger, P.; Adelman, N. B.; Beckman, K. J.; Campbell, D. J.; Ellis, A. B.; Lisensky, G. C. Journal of Chemical Education 1999, 76, 943-8.

2. Park, J.; An, K.; Hwang, Y.; Park, J.-G.; Noh, H.-J.; Kim, J.-Y.; Park, J.-H.; Hwang, N.-M.; Hyeon, T. Nature Mater. 2004, 3, 891-895.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/12105 must be provided.

1. Enhanced thermal stability of gold and silver nanorods through thin surface layers
2. Growth of gold tips onto hyperbranched CdTe nanostructures
3. Evaluation of deep-impurity governed photoelectrical properties in differently doped CdTe