Boundary effect on superconductivity in long single-crystal superconducting nanowires

Liu, Haidong; Ye, Zuxin; Luo, Zhiping; Rathnayaka, K. D. D.; Wu, Wenhao

doi:10.1016/j.physc.2007.08.029

Cited by 11 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In [7], the T c of a single Sn nanowire (21 μm long and 50 nm in diameter) in contact with Pb contacting layers was just below the T c of bulk lead. Liu et al [8] showed similar results on Sn and Zn nanowires in contact with Pb or Sn layers. The Sn and Zn nanowires (60 μm long and 200 nm in diameter) also displayed the T c of the contacting layers.…”

mentioning

confidence: 69%

“…We believe that these intriguing results might arise from this unexpected and spontaneous nanotube formation. The filamentary nanostructures measured in [7] and [8] could possibly be completely different from the ones expected. Instead, given the high growth rate observed here, they could consist of nanotubes having mostly the same composition as the massive bottom layer, serving as a cathode, with a limited inclusion of the metallic ions present in the initial electrolytic solution.…”

mentioning

confidence: 71%

See 1 more Smart Citation

Electroless template grown superconducting lead and tin nanotubes

2009

View full text Add to dashboard Cite

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 longrange proximity effect. Among the different techniques used to synthesize mesoscopic superconductors, electrodeposition into alumina and polymer membranes is now widely used [1]. Superconducting nanowires made from a variety of materials with a wide range of diameters have been synthesized allowing the investigation of one dimensional superconductivity phenomena [2, 3] and flux-line penetration in a confined geometry [4,5]. More recently, this template technique has been used to develop nanowires appropriate for the study of the proximity effect at superconductor-normal interfaces [6][7][8]. On the other hand, metallic nanotubes have also been fabricated by covering the walls of the pores of nanoporous media [9][10][11]. In most cases these nanotubes are synthesized by chemical (electroless) reduction of metal ions, which normally requires reducing agents and a metal catalyst that must be applied to the pore walls. This catalyst is usually formed with sensitization and activation steps. In the present work, we present an electroless synthesis of lead (Pb) and tin (Sn) nanotubes without sensitization, activation or a reducing agent. The simplicity of their synthesis makes this technique attractive to study superconductivity in this particular geometry. Some electrical transport measurements performed on these superconducting nanotubes are also presented.The nanotubes were prepared using 21 μm thick nuclear track etched polycarbonate membranes [12] having uniform pore diameters of either 250 or 480 nm and a pore density of 4 × 10 7 cm −2 . One face of the membrane is first coated with a thick layer of Pb or Sn, which closes all the pores. The

show abstract

mentioning

confidence: 69%

mentioning

confidence: 71%

Electroless template grown superconducting lead and tin nanotubes

2009

View full text Add to dashboard Cite

show abstract

“…Therefore, Pb nanowires thinner than ∼80 nm are potential candidates to study the complex quasi-1D superconducting transition and associated finite size effects. Low dimensional Pb nanostructures have been ext ensively studied for decades [19,[44][45][46][47][48][49]. Additionally, amorphous and granular nanowires of Pb and other materials ha ve been studied systematically [1,15,19].…”

Section: Pb Nanowiresmentioning

confidence: 99%

“…The superconductivity of the wire is expected to become more robust through its coupling with the superconducting reservoirs. It was observed in Figure 19a-c that single-crystal Zn nanowires of diameter 30-250 nm and length 6μm, using an in situ template-based electrochemical method [103], did not show any signature of superconductivity when they were in contact with Au electrodes, while Zn nanowires were superconducting at Tc(Sn) when they were in contact with Sn electrodes. And were superconducting at Tc(Pb) when they were in contact with Pb electrodes.…”

Section: Zn Nanowiresmentioning

confidence: 99%

Untitled

2016

Madridge J Nanotechnol Nanosci

View full text Add to dashboard Cite

Physical properties of quasi-one-dimensional superconducting nanowires can differ significantly from those of bulk superconductors. The reason behind is the impact of thermal and quantum fluctuations. In the particular case of resistive measurements, the fluctuations may significantly broaden the superconducting transition R(T). For superconducting wires with diameters decreasing, quantum phase slippage is an important process which can yield a non-vanishing wire resistance down to very low temperatures. Further decrease of the wire diameter results in proliferation of quantum phase slips causing a sharp crossover from superconducting to normal behaviour. The critical magnetic field exhibits quantumsize oscillations with pronounced resonant enhancements as a function of the wire radius. The understanding of the nature of superconductivity is often limited by the sample's morphology (e.g., disorder, defects, grain boundaries, or crystallinity). In order to identify the intrinsic phenomena in 1D, experimental studies of single crystal nanowires are clearly desirable. In this review, we present a summary of some recent activities in the field with main emphasis on experiment, while brief theoretical background is also presented.

show abstract

“…They tentatively suggest that phase fluctuations due to the small ∼ 0.02 K difference in the transition temperature of the two regions might be responsible for this. In another series of measurements by Liu et al [12], it was found that single crystal of superconducting nanowires of length between 6 and 60 µm superconductivity was induced on the wires when in contact with superconducting electrodes of higher critical temperature. These authors also conclude that the observed long-range proximity effect cannot be understood by existing theories.…”

Section: Introductionmentioning

confidence: 97%

Long-distance correlation-length effects and hydrodynamics ofHe4films in a Corbino geometry

2016

View full text Add to dashboard Cite

Previous measurements of the superfluid density ρs and specific heat for 4 He have identified effects that are manifest at distances much larger than the correlation length ξ3D [1-3]. We report here new measurements of the superfluid density which are designed to explore this phenomenon further. We determine the superfluid fraction ρs/ρ from the resonance of 34 nm films of varying widths 4 ≤ W ≤ 100 µm. The films are formed across a Corbino ring separating two chambers where a thicker 268 nm film is formed. This arrangement is realized using lithography and direct Si-wafer bonding. We identify two effects in the behavior of ρs/ρ : one is hydrodynamic, for which we present an analysis; and the other, a correlation-length effect which manifests as a shift in the transition temperature Tc relative to that of a uniform 34 nm film uninfluenced by proximity effects. We find that one can collapse both ρs/ρ and the quality factor of the resonance onto universal curves by shifting Tc as ∆Tc ∼ W −ν. This new scaling is a surprising result on two counts: it involves a very large length scale W relative to the magnitude of ξ3D; and, the dependence on W is not what is expected from correlation-length finite-size scaling which would predict ∆Tc ∼ W −1/ν .

show abstract

Boundary effect on superconductivity in long single-crystal superconducting nanowires

Cited by 11 publications

References 25 publications

Electroless template grown superconducting lead and tin nanotubes

Electroless template grown superconducting lead and tin nanotubes

Untitled

Long-distance correlation-length effects and hydrodynamics ofHe4films in a Corbino geometry

Contact Info

Product

Resources

About