Mossbauer analysis on the magnetic properties of Fe-Co nanoparticles synthesized by chemical vapor condensation process

Abstract

The magnetic properties of Fe-Co nanoparticles synthesized by chemical vapor condensation (CVC) process were investigated. Effect of CVC processing variables on the magnetic properties was analyzed in detail, using Mossbauer spectroscopy, XRD, BET and HRTEM. The synthesized particles were nearly spherical, and their surfaces were identified to be alpha-FeOOH, gamma-FeOOH and Fe3O4, but not alpha-Fe2O3. The magnetic properties were strongly influenced by CVC processing parameters. The increase of cobalt content had changed the magnetic property of the sample. However, when the decomposition temperature and the oxygen content in the carrier gas (Ar) were increased, the magnetic property reduced with decreasing the average particle size. Increasing the vacuum pressure in the chamber resulted in that the magnetic field reinforced with the increase of average particle size. (C) 2004 Elsevier B.V. All rights reserved.