Structural and magnetic properties of iron, cobalt and nickel nanoparticles

This study focuses on the synthesis and characterization of iron, cobalt and nickel nanoparticles through sol-gel method and heat-treating technique in argon atmosphere. The structure, morphology and magnetic properties of the as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) magnetometer. XRD studies indicated that the as-prepared products were iron, cobalt and nickel with well crystallized bcc, fcc and fcc structure, respectively. TEM observations showed that the as-synthesized products composed of spherical shape with size around 2, 2 and 2 nm for iron, cobalt and nickel, respectively. Magnetization results revealed that the as-obtained products showed superparamagnetic character at 300 K. The magnetic anisotropy of the products is much higher than that of bulk owing to the nanostructure. (C) 2011 Elsevier B.V. All rights reserved.