Structural and magnetic properties of starch-coated magnetite nanoparticles

Abstract

Magnetic Fe₃O₄ nanoparticles are prepared by the coprecipitation method and coated with starch as a surfactant. Their structural and magnetic behaviours are studied by means of X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Raman spectrum, Fourier Transform Infrared (FT-IR) as well as with a Vibrating Sample Magnetometer (VSM). The magnetic Fe₃O₄ nanoparticles under investigation have an average size of about 14 nm. The coated magnetic nanoparticles exhibit super-paramagnetic behaviours with a blocking temperature of about 170 K and saturation magnetisation ranging between 30 and 50 emu g⁻¹. In addition, the results of FT-IR indicated that interactions between the Fe₃O₄ particles and starch layers are much improved.

Keywords:

• magnetite nanoparticles
• surface modification
• colloidal stability
• magnetic stability

Acknowledgments

This work was supported by the research project No. QC.08.08 granted by Vietnam National University, Hanoi and the Fundamental Research Program of Vietnam under Project 410.406.