Nickel nanowires have been formed by stationary electrochemical deposition of nickel into mesoporous silicon templates from the modified Watts bath. Monitoring of the porous silicon potential during the electrochemical deposition has given the determination of the emergence of Ni on the outer surface of porous layer. Maximum filling factor of porous silicon with Ni has been achieved to 67%. The pore dimensions have been found to define the length and diameter of the Ni nanowires that have equaled to 10 mu m and 100-120 nm, respectively. The polycrystalline nature of the nickel nanowires, as well as the expansion of nickel lattice constant in comparison with bulk material has been established by analyzing the X-ray diffraction spectra. The synthesized samples have possessed ferromagnetic properties, which have been confirmed by temperature measurements of the magnetization. Smaller values of the specific magnetization of the Ni/PS samples and the atomic magnetic moment of Ni atoms at the low temperature with respect to those of bulk material have been suggested to be mostly caused by formation of nickel silicide at the beginning of the Ni electrochemical deposition. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.050210jes] All rights reserved

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We report on the superconducting properties of a Nb thin film deposited, with an interleaved insulating layer to avoid the proximity effect, on an array of ferromagnetic (Ni) nanowires embedded in a porous template. By investigating the Tc(H) phase boundary and by measuring V(I) characteristics and critical currents as a function of the applied magnetic field, we find that the Nb film exhibits properties similar to those of a network of one-dimensional superconducting nanowires. We attribute this behavior to the stray fields of the magnetic dipoles, which create an almost regular lattice of normal regions in the superconductor, ultimately changing its topology. Furthermore, there is evidence that the magnetic pinning of vortices is negligible in this structure.

Superconducting NbN nanonetworks with a very small number of interconnected nanowires, with diameter of the order of 4 nm, are fabricated combining a bottom-up (use of porous silicon nanotemplates) with a top-down technique (high-resolution electron beam lithography). The method is easy to control and allows to fabricate, on a robust support, devices with electrical properties close to a one-dimensional superconductor that can be fruitfully used for novel applications.

SERS-active substrates based on hybrid metallic nanovoids were formed by successive Ni electrodeposition and Ag electroless deposition in macroporous silicon. It was shown that the SERS signal intensity greatly depends on the morphology and elemental composition of hybrid melallization. Optimal regimes of metallization were found which provided fabrication of the most SERS-active substrates demonstrated 10 -11 M detection limit for rhodamine R6G.