Effect of carrier concentration on the normal transport properties and the superconducting transition temperature in theTl2Ba2Ca1−xYxCu2O8+ysystem

1991 ◽  
Vol 44 (6) ◽  
pp. 2757-2761 ◽  
Author(s):  
A. Poddar ◽  
P. Mandal ◽  
A. N. Das ◽  
B. Ghosh ◽  
P. Choudhury
Keyword(s):  
Transition Temperature ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Normal Transport

scholarly journals Unconventional Co-Existence of Insulating Nano-Regions and Conducting Filaments in Reduced SrTiO3: Mode Softening, Local Piezoelectricity, and Metallicity

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 437
Author(s):  
Annette Bussmann-Holder ◽  
Hugo Keller ◽  
Arndt Simon ◽  
Gustav Bihlmayer ◽  
Krystian Roleder ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Carrier Concentration ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
First Principles Calculations ◽  
Effective Electron ◽  
Mode Softening ◽  
Component Type ◽  
Electron Phonon Coupling ◽  
Transverse Optic

Doped SrTiO3 becomes a metal at extremely low doping concentrations n and is even superconducting at n < 1020 cm−3, with the superconducting transition temperature adopting a dome-like shape with increasing carrier concentration. In this paper it is shown within the polarizability model and from first principles calculations that up to a well-defined carrier concentration nc transverse optic mode softening takes place together with polar nano-domain formation, which provides evidence of inhomogeneity and a two-component type behavior with metallicity coexisting with polarity. Beyond this region, a conventional metal is formed where superconductivity as well as mode softening is absent. For n ≤ nc the effective electron-phonon coupling follows the superconducting transition temperature. Effusion measurements, as well as macroscopic and nanoscopic conductivity measurements, indicate that the distribution of oxygen vacancies is local and inhomogeneous, from which it is concluded that metallicity stems from filaments which are embedded in a polar matrix as long as n ≤ nc.

EFFECTS OF PLASMA OXIDATION ON TRANSPORT PROPERTIES OF SPUTTERED Y-Ba-Cu-O FILMS

1989 ◽  
Vol 03 (01) ◽  
pp. 87-92
Author(s):  
T. NOJIMA ◽  
S. AWAJI ◽  
Y. MAENO ◽  
T. FUJITA
Keyword(s):  
Transition Temperature ◽  
Transport Properties ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Plasma Oxidation ◽  
Normal Resistance ◽  
Before And After ◽  
Zero Resistance

Effects of plasma oxidation on superconducting and normal properties were studied for rf-sputtered Y-Ba-Cu-O films. The plasma oxidation was performed in a mixture gas of Ar-50%O 2 both before and after annealing. The oxidation enhances superconducting transition temperature, T c , and improves metal-like behavior of normal resistance as well. Typical films obtained after the oxidation exhibited the transition with an onset at 94 K and with zero resistance below 82 K. The improvement was found to hold for more than 30 days after oxidation.

TRANSPORT PROPERTIES OF La2-x1Srx1CuO4+δ/La2-x2Srx2CuO4+δ MULTILAYERS GROWN BY LASER ABLATION

2013 ◽  
Vol 27 (15) ◽  
pp. 1362029
Author(s):  
H. F. WANG ◽  
Y. Z. ZHANG ◽  
L. H. LIU ◽  
D. P. LI ◽  
G. Y. WANG ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Laser Ablation ◽  
Transport Properties ◽  
Low Temperatures ◽  
Superconducting Transition Temperature ◽  
Dominant Factor ◽  
Deposition Condition ◽  
Superconducting Transition ◽  
Charge Redistribution ◽  
Transport Measurements

A series of La 2-x1 Sr x1 CuO 4+δ/ La 2-x2 Sr x2 CuO 4+δ multilayers were epitaxially grown on (001) LaSrAlO 4 and (001) SrTiO 3 substrates by laser ablation, where x1 = 0.0, 0.08 (underdoped) and x2 = 0.24, 0.32, 0.45 (over-doped). Before the depositions of each multilayer, all of the single layers were deposited and characterized, and then the multilayers were deposited by using the same deposition condition except shifting targets for laser ablation. These multilayers are highly c-axis oriented. Several modulation wavelengths of the sublayers were selected for preparing the multilayers. The resistance measurements of these single layered films of La 2-x1 Sr x1 CuO 4+δ, La 2-x2 Sr x2 CuO 4+δ, and multilayers of La 2-x1 Sr x1 CuO 4+δ/ La 2-x2 Sr x2 CuO 4+δ were performed and compared. The transport measurements suggest that the charge redistribution may be a dominant factor for the superconducting transition temperature in low temperatures.

scholarly journals Thickness Dependence of Superconductivity in Layered Topological Superconductor β-PdBi2

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2826
Author(s):  
Huijie Li ◽  
Huanhuan Wang ◽  
Wenshuai Gao ◽  
Zheng Chen ◽  
Yuyan Han ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Transport Properties ◽  
Systematic Study ◽  
Superconducting Transition Temperature ◽  
Critical Thickness ◽  
Thickness Dependence ◽  
Superconducting Transition ◽  
Topological Superconductor ◽  
Physical Mechanisms

We report a systematic study on the thickness-dependent superconductivity and transport properties in exfoliated layered topological superconductor β-PdBi2. The superconducting transition temperature Tc is found to decrease with the decreasing thickness. Below a critical thickness of 45 nm, the superconductivity is suppressed, but followed by an abrupt resistance jump near Tc, which is in opposite to the behavior in a superconductor. We attribute suppressed Tc to the enhanced disorder as the thickness decreases. The possible physical mechanisms were discussed for the origination of sharply increased resistance in thinner β-PdBi2 samples.

Dependence of the Superconducting Transition Temperature on Carrier Concentration in Semiconducting SrTiO3

1965 ◽  
Vol 14 (9) ◽  
pp. 305-307 ◽  
Author(s):  
J. F. Schooley ◽  
W. R. Hosler ◽  
E. Ambler ◽  
J. H. Becker ◽  
Marvin L. Cohen ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Carrier Concentration ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition

CHARACTERISTICS OF Y1-xCaxBa2Cu3O7-δ THIN FILMS GROWN BY DC MAGNETRON SPUTTERING

2005 ◽  
Vol 19 (12) ◽  
pp. 581-584
Author(s):  
Z. WANG ◽  
Y. Z. ZHANG ◽  
X. F. LU ◽  
H. GAO ◽  
S. L. JIA ◽  
...  
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Superconducting Transition Temperature ◽  
Oxygen Atmosphere ◽  
Deposition Condition ◽  
Superconducting Transition ◽  
Dc Magnetron Sputtering ◽  
Annealing Pressure

Epitaxial Y 1-x Ca x Ba 2 Cu 3 O 7-δ thin films were successfully prepared by dc magnetron sputtering. The optimal deposition condition was determined. We find that the superconducting transition temperature Tc of thin films can be easily adjusted by annealing them in oxygen atmosphere with different pressures. Parabola curves are found for both Tc versus carrier concentration and Tc versus annealing pressure relations.

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