Non-saturating magnetic behaviour of a ferromagnetic semiconductor/metal nanocomposite

Nanostructuring of materials is a key trend in today's nanotechnology and drastically changes the physical properties of a material. The introduced system is a combination of nanostructured silicon and embedded nickel nanostructures. This composite material at the nanoscale is fabricated by anodization of silicon and a subsequent Ni deposition process, which leads to a system exhibiting new magnetic properties. Magnetization measurements of the hybrid system show two magnetic characteristics, a ferromagnetic one due to the spin-magnetism of the incorporated metal structures and an additional paramagnetic one occurring at applied magnetic fields far above the saturation magnetization of Ni. The ferromagnetic term depends on the geometry and the spatial distribution of the deposited metal structures, whereas the paramagnetic contribution is independent of the geometrical features of the precipitations. The occurrence of this term is currently under investigation and is related so far to a novel magnetism appearing at the interface between silicon and the deposited metal.