Properties of magnetite nanoparticles synthesized through a novel chemical route

We have developed a simple precipitation route to synthesize magnetite (Fe3O4) nanoparticles with controlled size without any requirement of calcination step at high temperatures. The study of these nanoparticles indicates an enhancement in saturation magnetization with reduction in size down to similar to 10 nm beyond which the magnetization reduces. The latter is attributed to surface effects becoming predominant as surface to core volume ratio increases. From the view-point of applications, 10 nm size of magnetite particles seems to be the optimum. (C) 2004 Elsevier B.V. All rights reserved.