E.A. Streltsov

On the morphology of Si/SiO 2 /Ni nanostructures with swift heavy ion tracks in silicon oxide

Si/SiO2/Ni nanostructures are fabricated by the irradiation of an oxidized Si surface with swift heavy ions, nanopore etching in the SiO2 layer, and the electrochemical deposition of nickel in the nanopores with their partial (∼50%) or complete filling. Studies of the morphology of the metal in the nanopores shows that the nickel-cluster structure is rather homogeneous and formed by crystallites ∼30–50 nm in size. The effects of deposition modes and structure morphology on current transport are analyzed with the use of test temperature dependences of the magnetoresistance. The reproducibility and stability of the magnetoresistance values for the case of homogeneous structure and pore filling with nickel make the Si/SiO2/Ni system promising for application as the base element for high-sensitivity low-temperature magnetic field sensors.

Underpotential shift in electrodeposition of metal adlayer on tellurium and the free energy of metal telluride formation

Underpotential deposition (UPD) of metals on polycrystalline tellurium film shows much similarity with UPD of metals on foreign metals, but the underpotential shifts on tellurium show no correlation with differences of work functions of the substrate and the deposited metal. In this work, we have evaluated the underpotential shifts of Pb, Cd, Zn, Bi, In, Sn, and Cu UPD on tellurium from cyclic voltammograms and potentiodynamic profiles of inverse charge transfer resistance derived from potentiodynamic impedance spectra, and shown a correlation of the underpotential shifts with the free energy of the corresponding metal telluride formation. The correlation can help to predict underpotential shifts for metals with complications in the measurement of this parameter.

Platinum electrochemical corrosion and protection in concentrated alkali metal chloride solutions investigated by potentiodynamic nanogravimetry

Platinum nanogravimetry potentiodynamic profiles in cyclic scans have shown significant dependence on alkali metal chloride concentration and effect of cations. Pt EQCM electrode mass drift in consecutive cyclic scans in 0.5 M LiCl, NaCl and CsCl was negative, similarly to the mass drift in aqueous solutions of H2SO4 with HCl additive, and this was due to electrochemical corrosion of platinum. The mass loss was prevented and inverted in 3 M solutions in the negative part of the scan, and the effect was attributed to shells of ion pairs firmly attached to the electrode surface via nonequilibrated Pt surface sites generated in the anodic scan. The increase in mass correlated with the increase in the Butterworth–van Dyke model resistance of quartz crystal resonator.

THERMAL CVD SYNTHESIS OF CARBON NANOTUBES IN SWIFT HEAVY ION TRACKS OF SILICON DIOXIDE

During the last years, a growing interest in the creation of micro- and nanoelectronic devices by use of the swift heavy ion track technology in a combination with carbon nanotubes (CNTs) is observed in several research centers worldwide. The CNTs were grown in etched ion tracks in SiO2 layers on Si. For this purpose, Ni-catalyst nanoclusters were electrochemically deposited within the ion tracks. The geometry of the obtained nanostructures has been analyzed. Structure features of CNTs obtained by thermal chemical vapor deposition have been investigated.