Full text loading...
Representative TEM images of the magnetite (a) hollow and (b) dense spheres. Photographs of powder samples of the (c) hollow and (d) dense spheres. SEM images of thin films of the (e) hollow and (f) dense spheres. The insets in (e) and (f) are photographs of the corresponding films of the hollow and dense particles, respectively. The scale bars are 500 nm in (a) and (b), and in (e) and (f).
Diffuse reflectance spectra for the powder samples of the magnetite hollow spheres (green solid curve) and the dense particles (black solid curve). Calculated reflectance spectra based on the theory of Mie scattering for the hollow spheres (green dashed curve) and the dense particles (black dashed curve) reproduce the peak positions of the experimental data. Note that the absolute experimental values are typically not reproduced by the calculations due to the approximation of the Kubelka–Munk approach.
Field dependence of magnetizations ( curves) at 300 K for the thin films of (a) the hollow spheres and (b) the dense particles, with magnetic field parallel and perpendicular to the film plane [see the inset of (a)]. Magnetizations are normalized by the value at 5 T.
Article metrics loading...