Investigation of Ni and Co Deposition into Porous Silicon and the Influence of the Electrochemical Parameters on the Physical Properties

Abstract

Metal-nanostructures are electrochemically deposited within the pores of porous silicon to achieve a hybrid material with specific magnetic properties. For this purpose first the porous silicon template is prepared by wet etching of an n+-type silicon wafer offering pore-diameters between 30 and 100 nm, depending on the anodization parameters. Secondly a ferromagnetic metal is electrodeposited into the pores, whereas the metal structures can be precipitated with various geometries and different spatial distributions depending on an accurate control of the deposition conditions. This method allows to deposit structures as spheres, ellipsoids or wires with a size up to a few micrometers in length whereas the diameter corresponds to the pore-diameter. In the case of Ni the deposition of small particles (2 - 5 nm) succeeded. These nanoparticles are covering the pore-walls and form depending on the packing density tube-like arrangements.