Figure 4

Temperature-dependent magnetization of magnetite-filled porous silicon, whereas the porous silicon matrices exhibit different morphologies. The particle size used was 8 nm in diameter. The lower blocking temperature (T_B ~ 130 K) results from nanoparticles within pores with an average diameter of 50 nm and a concomitant mean pore distance of 60 nm. The higher T_B ~ 160 K has been measured on a sample with pore diameters of about 90 nm and pore distances of about 35 nm.