Figure 10.

(a) Magnetization of porous silicon (pore-diameter ~50 nm, pore-distance ~50 nm) with embedded magnetite nanoparticles of 5 nm in size. This sample exhibits no magnetic anisotropy between the two magnetization directions perpendicular (full line) and parallel (dotted line) to the surface; (b) Zero field/field cooled magnetization of porous silicon with the same morphology with infiltrated 5 nm magnetite nanoparticles shows a blocking temperature (T_B) of about 10 K (Figure 10 b taken from [38]).