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In the frame of this paper, the synthesis of self-assembled magnetic and biocompatible nanovehicles movable in aqueous solutions by a magnetic field gradient is presented. The systems consist of a mesoporous silicon template and encapsulated iron oxide nanostructures, both materials known to be biocompatible. Two routes are applied to produce iron oxide nanostructures embedded within porous silicon. First, readily synthesized superparamagnetic iron oxide nanoparticles (NPs) are infiltrated into the pores. The second attempt is the chemical deposition of iron oxide structures inside the PSi templates. Concerning the adjustability of the magnetic properties of the system the loading procedure of the PSi with iron oxide NPs will be elucidated in detail as well as the growth of iron oxide structures within the pores. An assessment of the iron oxide deposition dependent on the template and the chemical parameters as well as of the magnetic properties in dependence on the particle size and template morphology of the nanocomposite will be presented. A further approach is the transition from a magnetite to the stable hematite phase by heat treatment of the specimens. A sufficient filling leading to a magnetization high enough for the movement of the nanovehicles within aqueous surroundings (e.g., body fluid) by magnetic field gradients could be reached easily. [ABSTRACT FROM AUTHOR]

In this paper, the magnetic interactions between metal nanostructures deposited within the pores of porous silicon will be elucidated. The influence of the morphology of the porous silicon which means a variation between high, medium, and low dendritic pore-growth as well as the morphology of the metal deposits (geometry, distribution and correlated branches to the template, respectively) on the magnetic behavior will be figured out. An increase in the uniformity of the pores resulting in smoother metal deposits leads to an increase in the coercivity of the nanocomposite which reveals less cross-talk between the nanostructures due to a modification of the stray fields. Also superparamagnetic nanoparticles of different sizes are incorporated within the pores and the dipolar coupling between them with regard to their sizes and their arrangements are investigated. [ABSTRACT FROM AUTHOR]