JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol.308, no.2, pp.289-295, 2007 (SCI-Expanded)
Magnetic nanoparticles of cobalt ferrite have been synthesized by wet chemical method using stable ferric and cobalt salts with oleic acid as the surfactant. X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) confirmed the formation of single-phase cobalt ferrite nanoparticles in the range 15-48 urn depending on the annealing temperature and time. The size of the particles increases with annealing temperature and time while the coercivity goes through a maximum, peaking at around 28 run. A very large coercivity (10.5 kOe) is observed on cooling down to 77 K while typical blocking effects are observed below about 260 K. The high field moment is (c) 2006 Elsevier B.V. All rights reserved.