ABSTRACT
Lead and tin nanotubes were synthesized by electroless deposition in a nanoporous polymer membrane without sensitization, activation or a reducing agent. A thick Pb or Sn layer is evaporated on one side of the membrane and provides the metallic ions needed to grow the tubes in an aqueous solution. The nanotubes' geometry and composition were investigated by means of electron microscopy, energy dispersive x-ray spectroscopy and ultramicrotomy. Electrical measurements obtained on such superconducting nanotubes are compared with solid wire characteristics. This spontaneous growth could explain some recent results obtained on superconducting nanowires showing an anomalous long-range proximity effect.
ABSTRACT
This article is focused on the use of electrodeposition and of various nanoporous templates for the fabrication of metallic nanowires made from single metals (Ni, Co, Pb, Sn), alloys (NiFe, CoFe, CoPt), and multilayers (Co/Cu, NiFe/Cu). An overview is given of our recent studies performed on both magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also discussed.
Subject(s)
Crystallization/methods , Electric Wiring , Electrochemistry/methods , Magnetics/instrumentation , Metals/chemistry , Nanotechnology/methods , Nanotubes/chemistry , Crystallization/trends , Electric Conductivity , Electrochemistry/instrumentation , Nanotechnology/instrumentation , Nanotechnology/trends , Nanotubes/analysisABSTRACT
Applying a constant voltage to superconducting nanowires we find that its I-V characteristic exhibits an unusual S behavior. This behavior is the direct consequence of the dynamics of the superconducting condensate and of the existence of two different critical currents: j(c2) at which the pure superconducting state becomes unstable and j(c1)
