The effects of the substitution for Ba-sites on the transition temperature of high-Tc superconductors

2004 ◽  
Vol 406 (1-2) ◽  
pp. 9-14 ◽  
Author(s):  
Z.H. Yang ◽  
D.N. Shi
Keyword(s):  
Transition Temperature ◽  
High Tc Superconductors ◽  
High Tc

Structural and Superconducting Properties of RE1 - 2xPrxCaxSr0.8Ba1.2Cu3O7 - δ (RE = Er and Gd) High Tc Superconductors

2003 ◽  
Vol 17 (13) ◽  
pp. 2609-2622 ◽  
Author(s):  
N. Charoenthai ◽  
P. Winotai ◽  
R. Suryanarayanan ◽  
I. M. Tang
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Transition Temperature ◽  
Size Effect ◽  
High Temperature Superconductors ◽  
Superconducting Properties ◽  
High Tc Superconductors ◽  
High Tc ◽  
Oxygen Annealing ◽  
Ion Size

We report here on the structural and superconducting properties of RE 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ (RE = Er and Gd, 0 ≤ x ≤ 0.2) high temperature superconductors. The transition temperature (Tc) of these compounds decreases when the Pr and Ca concentrations are increased. At constant Pr and Ca concentrations, the Tc of Er 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ superconductor system is higher than that observed for the Gd 1 - 2x Pr x Ca x Sr 0.8 Ba 1.2 Cu 3 O 7 - δ system. For the Gd 0.8 Pr 0.1 Ca 0.1 Sr 0.8 Ba 1.2 Cu 3 O 7 - δ sample, after heating in argon followed by oxygen annealing, the orthorhombicity increases accompanied by 10 K increase in Tc. These results show that though our data indicate an ion-size effect, the Tc suppression rate dTc/dx depends very much on the heat treatment adopted to prepare the samples.

ANHARMONIC MODEL FOR HIGH-Tc SUPERCONDUCTORS

1987 ◽  
Vol 01 (03n04) ◽  
pp. 1071-1088 ◽  
Author(s):  
N.M. Plakida ◽  
V.L. Aksenov ◽  
S.L. Drechsler
Keyword(s):  
Experimental Data ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
High Tc Superconductors ◽  
High Tc ◽  
Perovskite Type

A considerable enhencement of the superconducting transition temperature Tc in perovskite-type oxides is explained in the framework of the anharmonic model for superconductors with structurally unstable lattices. It is shown that interaction of electrons with highly anharmonic oxigen-ion vibrations of a rotational type results in a sufficiently large couplings constant λ. The obtained estimation for Tc is in agreement with experimental data for La(Y)BaCuO systems.

Pressure dependence of transition temperature in selected high-Tc superconductors

1990 ◽  
Vol 3 (1-6) ◽  
pp. 117-119 ◽  
Author(s):  
R. Sieburger ◽  
J. Diederichs ◽  
H. Goßner ◽  
H. Neumaier ◽  
W. Reith ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Pressure Dependence ◽  
High Tc Superconductors ◽  
High Tc

SUBGAP INDUCED BY BILAYER EFFECTS OF CuO2 PLANES IN HIGH Tc SUPERCONDUCTORS

2003 ◽  
Vol 17 (29n30) ◽  
pp. 1495-1500
Author(s):  
JE HUAN KOO ◽  
GUANGSUP CHO
Keyword(s):  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
High Tc Superconductors ◽  
Zero Bias ◽  
High Tc ◽  
Zero Bias Conductance

The bilayer effects of CuO 2 planes in high-T c superconductors are investigated. The interaction between a CuO 2 bilayer is found to induce a subgap far below the superconducting transition temperature T c . It is also shown that zero-bias-conductance-peaks (ZBCP) above T c are due to a Kondo-type effect as for low-T c superconductors, but ZBCP far below T c originating from this bilayer effects are different from traditional explanations.

scholarly journals High-Tc Superconductors: Evidence on the Electron?Phonon Interaction from Transport Measurements

1988 ◽  
Vol 41 (4) ◽  
pp. 597 ◽  
Author(s):  
AB Kaiser ◽  
C Uher
Keyword(s):  
Thermal Conductivity ◽  
Transition Temperature ◽  
Transport Properties ◽  
Hall Coefficient ◽  
Electronic Transport ◽  
Normal State ◽  
High Tc Superconductors ◽  
Phonon Interaction ◽  
High Tc ◽  
Electron Phonon Interaction

We discuss the interpretation of measurements of thermal conductivity, thermopower, Hall coefficient, resistivity and mapetorcsistance in hiJh-temperaturc superconductors. The thermal conductivity of YBa2 Cu3 07 shows an increase below the transition temperature 7;:, demonstrating the importance of the electron-phonon interaction in reducing the phonon current in the normal state. Many features of resistivity and thermopower can be interpreted in terms of conventional metallic models, although morc exotic interpretations have been proposed. We show how measurements on morc disordered samples should help resolve controversy regarding the interpretation of the electronic transport properties.

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