Journal of Optoelectronics and Advanced Materials Vol. 7, No. 2, April 2005, p. 865 - 870 Ni NANOWIRES ELECTRODEPOSITED IN SINGLE ION TRACK TEMPLATES M. Daub a, c , I. Enculescu a,b* , R. Neumann a , R. Spohr a a Gesellschaft für Schwerionenforschung (GSI), Planckstr. 1, 64291 Darmstadt, Germany b National Institute of Materials Physics, Atomistilor 105, 76900 Bucuresti-Magurele, Romania c Current address: Max-Planck-Institute for Microstructure Physics, Weinberg 2, 06120 Halle, Germany 30-μm thick polycarbonate foils were irradiated with single swift heavy ions (e.g. Au 11.4 MeV/nucleon). After etching with solutions containing NaOH and methanol, templates containing single conical pores were obtained. The size and the shape of the nanopores depend on etching conditions such as time of etching, concentration and temperature of the etching solution. By electrochemical deposition of nickel, nanowires were grown in the single pores. The nanowires were contacted by sputtering a gold layer on top of the membrane. The magnetic measurements indicated that the nanowires possess around 1% anisotropic magnetoresistance. The current-voltage characteristic of a Ni nanowire shows a linear behavior for current densities smaller than 10 8 A/cm 2 . The maximum current density that a single Ni wire can withstand was found to be 3×10 8 A/cm 2 . (Received June 24, 2004; accepted March 23, 2005) Keywords: Electrodeposition, Nanowires, Anisotropic magnetoresistance 1. Introduction Magnetic nanowires represent an important family of magnetic structures, which during the last few years attracted an increased interest arising from unique physical (e.g. electronic, optical, magnetic, mechanical) properties on account of their very restricted size. In addition, their numerous potential applications in a variety of fields, such as physics, chemistry, materials and biosciences, help promote investigations on these novel nanostructures. Among the methods used in order to obtain nanowires, the filling of channels in a template is a straightforward approach. This technique consists in synthesizing the desired wires within the pores of a membrane [1,2]. Ion track membranes provide significant advantages over other usable templates, particularly in view of the degree of freedom they offer to produce nanowires of a specific number and with different compositions. The host template can be made from a range of materials including polymers and glasses, the most widely used being polycarbonate, polyimide and polyethylene. The method of producing nanowires by means of ion track membranes consists of several steps: (1) irradiation of a polymer film with swift heavy ions in order to create long, narrow and absolutely straight damage trails along the ion trajectories; (2) conversion of these so-called latent tracks into thin pores by chemical etching; (3) filling of pores with a large variety of materials [3,4,5]. Recent progress on magnetism and magnetic materials has made the magnetic nanowires a particularly interesting class of objects for both scientific and technological applications. For example, research on subjects such as giant magnetoresistance [2, 6], anisotropic magnetoresistance * Corresponding author: encu@infim.ro