Electron Tunneling Measurement of a Small Energy Gap in Lanthanum

1966 ◽  
Vol 17 (4) ◽  
pp. 196-198 ◽  
Author(s):  
A. S. Edelstein ◽  
A. M. Toxen
Cryogenics ◽  
1987 ◽  
Vol 27 (5) ◽  
pp. 227-228 ◽  
Author(s):  
J Moreland ◽  
A.F Clark ◽  
H.C Ku ◽  
R.N Shelton

2019 ◽  
Vol 10 (31) ◽  
pp. 7352-7357 ◽  
Author(s):  
Zhu Mao ◽  
Zhan Yang ◽  
Chao Xu ◽  
Zongliang Xie ◽  
Long Jiang ◽  
...  

Small energy gap boosts dual-channel triplet harvesting via TADF and UOP, which suppresses long-lived triplet concentration quenching. An infrared laser (808 nm) is able to induce persistent emission under ambient conditions.


2015 ◽  
Vol 832 ◽  
pp. 28-53 ◽  
Author(s):  
Hani Nasser Abdelhamid

Recently, numerous delafossite oxides in nanoscale have been reported for diverse applications. The present review summarized the recent overall views of delafossite nanoparticles in diverse applications such as energy, catalysis, photocatalysis, nanomedicine, sensors, electrochemical devices and environmental concerns. Delafossite nanoparticles possess unique features such as different and wide chemical composition, large surface area, small energy gap, ability for further functionalization, possess dual-active sites with different oxidation states (A+and M3+), and eager for doping with various species with feasibility to undergo structure modification. Thus, they provided promising application such as solar cell, photocatalysis, hydrogen production, bioactive materials, separation purposes and others. Pros, cons, current and future status were also reviewed.


1995 ◽  
Vol 09 (18) ◽  
pp. 1175-1184
Author(s):  
M. MORENO ◽  
R.M. MÉNDEZ-MORENO ◽  
S. OROZCO ◽  
M.A. ORTÍZ

A model with anomalous occupancy is applied to Hg-based cuprate superconductors. The anomaly consists of a small energy gap near the Fermi surface, the scale of the gap anomaly is of order of the cutoff (v.g. Debye) energy. Values of the anomalous occupancy parameters for Hg-based superconductors are obtained for different values of the ratio R and the effective coupling constant, within the weak coupling. As these materials have the highest transition temperature known for layered copper-oxide superconductors, they serve as a new testing ground for various proposed models.


MRS Bulletin ◽  
1990 ◽  
Vol 15 (6) ◽  
pp. 44-49 ◽  
Author(s):  
J.M. Valles ◽  
R.C. Dynes

Electron tunneling measurements have proven enormously valuable in studies of conventional superconductors. Very early measurements confirmed, in an especially convincing way, the existence of the superconducting energy gap, and more detailed studies demonstrated the spectral form of the gap and its temperature dependence. These measurements were instrumental in confirming in some detail the predictions of the Bardeen, Cooper, Schrieffer (BCS) theory of superconductivity in simple metals. For example, it was shown very clearly that the ratio of the energy gap (2Δ) and critical temperature Tc was close to the BCS value (2Δ/kTc = 3.5). As the sophistication of the technique improved, deviations from this BCS weak coupling limit became apparent (2Δ/kTc was measured to be >4 in materials like Pb, for example), and subtle structure in the current-voltage characteristics of tunnel junctions unearthed a signature of the electron-phonon interaction—the microscopic mechanism responsible for superconductivity in these traditional materials. Through a quantitative analysis of this structure, people were able to extract a function α2(ω)F(ω), which is the phonon density of states F(ω) modulated by the electron-phonon coupling function α2(ω). This function gave a quantitative description of the electron-phonon interaction and confirmed beyond a doubt that the electron-phonon interaction was responsible for superconductivity.


1987 ◽  
Vol 35 (16) ◽  
pp. 8853-8855 ◽  
Author(s):  
M. F. Crommie ◽  
L. C. Bourne ◽  
A. Zettl ◽  
Marvin L. Cohen ◽  
A. Stacy

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