Silicon/Metal Hybrid Nanosystem with Tailored Magnetic Properties in Two Characteristic Field Regions

Abstract

Electrodeposition of ferromagnetic metal-nanostructures into a porous silicon (PS) matrix merges the electronic properties of a semiconductor and the ferromagnetic ones of the precipitated metal on one material level. The deposition is performed using a metal-salt solution as electrolyte and an applied pulsed current under cathodic conditions. The metal precipitation within a PS-template exhibiting unconnected mesopores with aspect ratios of about 1000 leads to nanostructures with a maximum elongation of a few microns (aspect ratio 100). The achieved hybrid system exhibits magnetic characteristics which drastically differ from the corresponding bulk materials. Magnetization measurements of this material show two characteristics, one at magnetic fields below the saturation magnetization MS of the deposited metals due to the spin-magnetism (e.g. MS (Ni)=0.62 T, MS (Co)=1.82 T) and another one at higher fields above MS which is assigned to a novel, recently intensively investigated magnetic contribution likely caused by spin-orbit interaction.