Superconducting energy gap and transition temperature of amorphous Pb55Bi45-films

1977 ◽  
Vol 28 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Chr Fuchs ◽  
J. Hasse
1987 ◽  
Vol 01 (02) ◽  
pp. 555-559 ◽  
Author(s):  
Hongjie TAO ◽  
Yingfei CHEN ◽  
Li LU ◽  
Qiansheng YANG ◽  
Bairu ZHAO ◽  
...  

We have carried out superconducting energy gap measurements for polycrystalline perovskite-structure superconductors YBaCuO, LaSrCuO and BPBO with point contact tunneling. The tunneling conductance curves for YBaCuO, LaSrCuO and BPBO show the energy gap to transition temperature ratio 2Δ/kTc =4.7, 7.8 and 5.05 respectively, which is consistant with the strong-coupling superconductivity.


1968 ◽  
Vol 46 (9) ◽  
pp. 1129-1132 ◽  
Author(s):  
D. G. Walmsley ◽  
C. K. Campbell ◽  
R. C. Dynes

This note presents the results of superconductive tunneling measurements which show that very thin (50–100 Å) aluminium films exhibit a unique superconducting energy gap. The temperature dependence of this gap is BCS-like, and the ratio of the gap magnitude—as extrapolated to T = 0 °K (2Δ(0))—to the observed transition temperature, Tc, remains close to the usual BCS value of 3.52 k. The effect of crystallite size on deviations from BCS results is also discussed in relation to experimental observations.


1984 ◽  
Vol 62 (8) ◽  
pp. 776-779 ◽  
Author(s):  
R. J. Kennedy ◽  
B. P. Clayman

The superconducting energy gaps of small particles (1–10 μm) of 2H–NbS2 and 2H–NbSe2 have been measured by far-infrared (FIR) transmission spectroscopy. Comparison of these results with previous FIR measurements made on millimetre-size single crystals of 2H–NbSe2 validates the use of the novel method of sample preparation used here. Comparison of the gap frequencies (νg) with the superconducting transition temperature (Tc) determined by magnetic susceptibility measurements indicates that 2H–NbS2, unlike 2H–NbSe2, exhibits non-Bardeen–Cooper–Schrieffer (BCS)-like behaviour, with hνg/kTc = 2.3.


2004 ◽  
Vol 69 (10) ◽  
Author(s):  
I. K. Yanson ◽  
S. I. Beloborod’ko ◽  
Yu. G. Naidyuk ◽  
O. V. Dolgov ◽  
A. A. Golubov

MRS Bulletin ◽  
1990 ◽  
Vol 15 (6) ◽  
pp. 31-33
Author(s):  
M. Brian Maple

This issue of the MRS BULLETIN is devoted to high Tc superconductivity. It is the sequel to a previous series of articles on the same subject which appeared in the MRS BULLETIN in January 1989. While the articles in the January 1989 issue emphasized the families of high Tc superconducting oxides known at that rime, as well as novel processing techniques and thin films, the papers in this issue focus on the physical properties of high Tc oxide superconductors.The quality of polycrystalline and single-crystal bulk and thin-film materials has improved to the point where researchers can now make reliable measurements of many physical properties representative of the intrinsic behavior of these materials. As a result, a broad spectrum of important issues such as the nature of the electronic structure, the type of superconducting electron pairing, the magnitude and temperature dependence of the superconducting energy gap, the behavior of fluxoids in the vortex state, etc., can be addressed meaningfully. Presently emerging is a consistent picture of the physical properties of the high Tc oxides, which will form the foundation to eventually developing an appropriate theory for the normal and superconducting states of these remarkable materials.


2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Hai-Li Li ◽  
Guoyang Fu ◽  
Yan Liu ◽  
Jian-Pin Wu ◽  
Xin Zhang

Abstract In this paper, we construct a novel holographic superconductor from higher derivative (HD) gravity involving a coupling between the complex scalar field and the Weyl tensor. This HD coupling term provides a near horizon effective mass squared, which can violates IR Breitenlohner–Freedman (BF) bound by tuning the HD coupling and induces the instability of black brane such that the superconducting phase transition happens. We also study the properties of the condensation and the conductivity in the probe limit. We find that a wider extension of the superconducting energy gap ranging from 4.6 to 10.5 may provide a novel platform to model and interpret the phenomena in the real materials of high temperature superconductor.


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