427310.fig.002a
(a)
427310.fig.002b
(b)
Figure 2: TEM micrographs of (a) Fe3O4/SiO2 nanoparticles prepared by sonication; inset shows an individual Fe3O4/SiO2 nanoparticles and (b) Fe3O4/SiO2 nanoparticles prepared by the stirring method.