Template-Morphology Dependent Deposition of Ferromagnetic Metals

Porous silicon templates with different morphologies have been fabricated offering a self-organized pore-arrangement. The morphology has been varied in a broad range with pore-diameters between 25 and 100 nm but also especially with respect to the roughness of the pore-walls. These templates have been filled with diverse ferromagnetic metals and alloys by electrodeposition. The aim of this work is to fabricate self-organized three dimensional arrays of magnetic nanostructures (wires, particles) with distinct magnetic characteristics within a non-magnetic mattrix. The magnetic properties strongly depend on the shape and size of the deposited nanostructures, their mutual arrangement within the pores as well as on the morphology of the template. Also the texture of the pore-surface plays a key role concerning magnetic coupling between adjacent pores. Furthermore the kind of metal is of importance, whereat for each metal the deposition parameters have to be adjusted individually. The deposition process has been elucidated with respect to the morphology of the template, especially the dendritic pore-growth and the resulting structure of the deposits. The nucleation of the metal deposition starts at surface asperities and the growth of the nanostructures can be influenced by using pulsed electrodeposition and also by the electrolyte. A study of the dependence of the metal deposition on the morphology and the resulting adjustability of the magnetic properties of the 3-dimensional nanostructure array will be presented.