Chinese Science Bulletin

, Volume 56, Issue 22, pp 2383–2388

Characterization of γ-Fe2O3 nanoparticles prepared by transformation of α-FeOOH

  • Hua Miao
  • Jian Li
  • YueQiang Lin
  • XiaoDong Liu
  • QingMei Zhang
  • Jun Fu
Open AccessArticle Materials Science

DOI: 10.1007/s11434-011-4559-z

Cite this article as:
Miao, H., Li, J., Lin, Y. et al. Chin. Sci. Bull. (2011) 56: 2383. doi:10.1007/s11434-011-4559-z

Abstract

γ-Fe2O3 nanoparticles were successfully synthesized by a chemically induced transformation of α-FeOOH. In this method, the precursor (α-FeOOH) was prepared by chemical precipitation, and then treated with a mixed FeCl2/NaOH solution to produce the nanoparticles. X-ray diffraction indicated that when the precursor was treated with FeCl2 (0.22 mol/L) and NaOH (0.19 mol/L), pure γ-Fe2O3 nanoparticles were obtained. However, when the concentration of FeCl2 was <0.22 mol/L or the concentration of NaOH was <0.19 mol/L, α-FeOOH and γ-Fe2O3 phases co-existed in the nanoparticles. Transmission electron microscopy observations showed that in the samples with co-existing phases, the nanoparticles did not have identical morphologies. The pure γ-Fe2O3 nanoparticles were polygonal rather than spherical. The volume ratio of α-FeOOH and γ-Fe2O3 was estimated for the two-phase samples from magnetization data obtained from a vibrating sample magnetometer. This chemically induced transformation is novel, and could provide an effective route for the synthesis of other metal oxide nanocrystallites.

Keywords

α-FeOOHγ-Fe2O3FeCl2/NaOH solutiontransitionnanoparticles
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© The Author(s) 2011

Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

Authors and Affiliations

  • Hua Miao
    • 1
  • Jian Li
    • 1
  • YueQiang Lin
    • 1
  • XiaoDong Liu
    • 1
  • QingMei Zhang
    • 1
  • Jun Fu
    • 1
  1. 1.School of Physics Science and Technology & MOE Key Laboratory on Luminescence and Real-Time AnalysisSouthwest UniversityChongqingChina