Associated Group

We apply nanostructured silicon as a matrix to fabricate self-organized ferromagnetic/semiconducting composites by chemical and electrochemical methods. The matrix formation allows the tuning of the pore diameters in a broad range from a few nanometers to several micrometers. The quasi-regular pore-arrays are preferentially filled with magnetic materials electrochemically or by chemical reduction to produce magnetic nanostructures with defined geometry. Our investigations mainly focus on the structural and magnetic properties of these hybrid materials, as the magnetic response strongly depends on the size, geometry and spacings of the deposits. We pursue two main directions concerning the applicability in, first, magneto-electronics and, second, in biomedicine for magnetically guided drug delivery. With respect to the latter, we in particular examined the iron oxide nanoparticle size dependence in the context of magnetic interactions.

• Vibrating Sample Magnetometer (VSM)
• Electrochemical cell arrangement for anodization of silicon to produce nanostructured silicon.
• Electrochemical cell arrangement for metal deposition within nanostructured silicon to achieve semiconducting/ferromagnetic composite systems.

The magnetic response is recorded with the Vibrating Sample Magnetometer (VSM). We can work in a broad temperature range (5 K – 1273 K), which allows to determine the Curie temperature of the systems. First order reversal curves (FORC), which can be performed due to the high measuring velocity of the instrument, are used to get detailed knowledge about the magnetic cross-talk between the metal deposits.