ChemInform Abstract: Synthesis and Characterization of Nanometer-Size Fe3O4 and γ- Fe2O3 Particles.

✍ Scribed by Y. S. KANG; S. RISBUD; J. F. RABOLT; P. STROEVE

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 32 KB
• Volume: 28
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199702030

✦ Synopsis

Synthesis and Characterization of Nanometer-Size Fe3O4 and γ-Fe2O3 Particles.

-Clear transparent hydrosols of magnetite with Fe3O4 particles of less than 10 nm diameter are prepared from aqueous FeCl3-FeCl2 solutions with a molar ratio of Fe(II)/Fe(III) = 0.5 and pH 11-12 without use of a surfactant. Oxidation of Fe3O4 nanoparticles in the aqueous phase by adjusting the pH to ≈3.5 and stirring in air at 100 • C yields a hydrosol of γ-F2O3 nanoparticles. Aggregates of γ-Fe2O3 nanoparticles, obtained by addition of 1.5 M NaOH solution to the colloidal solution to adjust the pH to 11, show paramagnetic behavior. -(KANG, Y. S.; RISBUD, S.; RABOLT,