SUPERCONDUCTING PROPERTY IN Mn DOPED La1.85Sr0.15CuO4 SYSTEM

2005 ◽  
Vol 19 (01n03) ◽  
pp. 303-305 ◽  
Author(s):  
CHANGJIN ZHANG ◽  
J. S. KIM ◽  
B. H. KIM ◽  
Y. W. PARK
Keyword(s):  
Transition Temperature ◽  
Superconducting Property ◽  
Magnetic Impurities ◽  
Pair Breaking ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Breaking Effect ◽  
Mn Doping ◽  
Magnetic Pair ◽  
Mn Doped

In this paper the superconducting properties in La 1.85S Sr 0.15 Cu 1-x Mn x O 4 and La 1.85-2x Sr 0.15+2x Cu 1-x Mn x O 4 samples are discussed. The superconducting transition temperature keeps constantly at 37 K for all superconducting samples. The suppression of superconductivity in these systems does not fit the Arbrikosov and Gork'ov theory which predicts that Tc should decrease in the presence of magnetic impurities in the lattice. The magnetic pair-breaking effect is not the reason for the suppression of superconductivity in Mn doping systems. The localization of carriers in the CuO 2 plane induced by Mn doping should be responsible for the suppression of superconductivity.

scholarly journals Distinct superconducting properties and hydrostatic pressure effects in 2D α- and β-Mo2C crystal sheets

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Yunjie Fan ◽  
Chuan Xu ◽  
Xiang Liu ◽  
Chao Ma ◽  
Yuewei Yin ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Hydrostatic Pressure ◽  
Electronic Properties ◽  
Superconducting Transition Temperature ◽  
Important Influence ◽  
Pressure Effects ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Disordered Carbon

Abstract Recently, 2D Mo2C, a new member of the MXene family, has attracted much attention due to the exotic superconducting properties discovered in 2D α-Mo2C. Here, not only 2D α-Mo2C but also 2D β-Mo2C crystal sheets with distinct disordered carbon distributions were successfully grown. 2D β-Mo2C shows a much stronger superconductivity than 2D α-Mo2C, and their superconductivities have different hydrostatic pressure responses. The superconducting transition temperature Tc of 2D α-Mo2C shows a dome-shaped profile under pressure, implying the existence of two competing effects arising from phononic and electronic properties, while for 2D β-Mo2C, Tc decreases monotonically with increasing pressure, possibly due to phonon stiffening. These results indicate that the electronic properties have a more important influence on the superconductivity in 2D α-Mo2C compared to 2D β-Mo2C. The ordered and disordered carbon distributions in 2D α-Mo2C and β-Mo2C, respectively, may be the underlying origin for their different electronic and superconducting properties.

SUPERCONDUCTIVITY IN THE Bi-Pb-Sr-Ca-Cu-O SYSTEM DOPED WITH Sb

1990 ◽  
Vol 04 (01) ◽  
pp. 131-141 ◽  
Author(s):  
J. HEIRAS ◽  
W. KRAUSS ◽  
C. POLITIS
Keyword(s):  
Transition Temperature ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Rays ◽  
Superconducting Transition ◽  
Melting Behaviour ◽  
Superconducting Properties ◽  
Thermo Gravimetric ◽  
Preparation Methods ◽  
Annealing Conditions

Doping of Bi-Pb-Sr-Ca-Cu-O HTSC's with Sb have been attempted with the purpose of increasing the transition temperature. Several different preparation methods were investigated in which the composition and annealing conditions were varied; ρ vs T and χ vs T measurements were carried out to determine the superconducting properties of samples. X-rays, differential thermal analysis (DTA) and thermo gravimetric analysis (TG) were performed to study the structure and the melting behaviour of samples. However, it was found that, at least for the conditions tested, Sb has no effect in increasing the transition temperature of this system. The maximum superconducting transition temperature observed in the system Bi 2−x Pb x Sr 2 Ca 2 Cu 3 O y was T c,o = 108 K which was completely independent of the doping with Sb.

High Pressure Properties of Superconducting Material Palladium

2013 ◽  
Vol 813 ◽  
pp. 327-331
Author(s):  
Wei Min Peng ◽  
Zhong Li Liu ◽  
Hong Zhi Fu
Keyword(s):  
High Pressure ◽  
Perturbation Theory ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Density Functional ◽  
High Pressures ◽  
Ambient Pressure ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Density Functional Perturbation Theory

The electronic and the superconducting properties of Pd were studied in the framework of density functional perturbation theory. We explored the superconducting transition temperature for bulk Pd and predicted possible superconductivity at ambient and high pressures. It is found that of Pd is 0.0356 K at ambient pressure and it decreases with pressure.

scholarly journals Single Crystal Growth and Superconducting Properties of Antimony Substituted NdO0.7F0.3BiS2

2017 ◽  
Author(s):  
Satoshi Demura ◽  
Satoshi Otsuki ◽  
Yuita Fujisawa ◽  
Hideaki Sakata
Keyword(s):  
Crystal Growth ◽  
Transition Temperature ◽  
Single Crystal ◽  
Superconducting Transition Temperature ◽  
Single Crystal Growth ◽  
Layered Superconductor ◽  
Superconducting Transition ◽  
Large Decrease ◽  
Superconducting Properties ◽  
Chemical Pressure

Antimony (Sb) Substitution less than 10 % is examined on a single crystal of a layered superconductor NdO0.7F0.3BiS2. Superconducting transition temperature of the substituted samples decreases with increasing Sb concentration. A lattice constant along the c axis showed a large decrease compared with that along the a axis. Since in-plane chemical pressure monotonically decreases with increasing Sb concentration, the suppression of the superconductivity is well described in terms of the decrease in in-plane chemical pressure.

scholarly journals Superconducting properties of very high quality NbN thin films grown by pulsed laser deposition

2019 ◽  
Vol 70 (7) ◽  
pp. 89-94
Author(s):  
Serhii Volkov ◽  
Maros Gregor ◽  
Tomas Roch ◽  
Leonid Satrapinskyy ◽  
Branislav Grančič ◽  
...  
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Pulsed Laser ◽  
Domain Size ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Si Substrate ◽  
Coherent Domain Size ◽  
Coherent Domain

Abstract In this work, we study the effect of the various substrates on the growth and superconducting properties of NbN thin films grown by using pulsed laser ablation in a N2 + 1%H2 atmosphere on MgO, Al2O3 and Si substrates. Structural and superconducting analyses of the films demonstrate that using MgO and Al2O3 substrates can significantly improve the film properties compared to Si substrate. The X-ray diffraction data indicate that MgO and Al2O3 substrates produce highly oriented superconducting NbN films with large coherent domain size in the out-of plane direction on the order of layer thickness and with a superconducting transition temperature of 13.1 K and 15.2 K, respectively. On the other hand, the NbN film grown on the Si substrate exhibits random polycrystalline orientation. Together with the smallest coherent domain size it leads to the lower critical temperature of 8.3 K. Finally, by using a passivation surface layer we are able to improve superconducting properties of NbN thin film and we observe superconducting transition temperature 16.6 K, the one of the highest value reported so far for 50 nm thick NbN film on sapphire.

Role of Silver in Yba2Cu3AgXO7-δ Composite Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
L. Ganapathi ◽  
Ashok Kumar ◽  
J. Narayan
Keyword(s):  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Alloy Formation ◽  
Peritectic Transformation ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
Low Concentrations ◽  
Composite Superconductors ◽  
Silver Metal

AbstractSuperconducting properties and microstructures of the YBa2Cu3AgxO7‐δ composites have been studied as a function of silver content, 0 ≤ x ≤ 6, using a variety of techniques.The superconducting transition temperature,Tc, of these composites was found to be the same, ∼ 90 K, for the above range of compositions. The composites with x > 3 are found to have resistivity behavior identical to silver metal above the superconducting transition temperature. The peritectic transformation temperature of the 123 material in the composite is lowered. Alloy formation between Ag and Cu is proposed to take place triggering the peritectic transformation at lower temperatures. The silver is observed in the form of precipitates at very low concentrations of silver, indicating that silver does not substitute for copper in YBa2Cu3AgxO7. Lattice parameters of the composites were found to be invariant throughout the above composition range. The addition of Ag2O in the starting composition seems to stabilize the stoichiometric YBa2Cu3AgxO7 by way of decomposition to Ag and O, also, the better diffusion of oxygen through silver in comparison with that through the superconductor helps the regeneration of superconductivity in the composite superconductor. As a result, the incorporation of oxygen and recovery of superconducting properties is enhanced in the silver composites.For values of x > 3 small quantities of 211 phase were detected along the grain boundaries, which makes the residual composition poor in copper resulting in the formation of non‐superconducting 211 phase.

A magnetic pair-breaking effect in rare earth-doped manganites

1998 ◽  
Vol 250 (4-6) ◽  
pp. 435-438 ◽  
Author(s):  
J. Pierre ◽  
A. Nossov ◽  
V. Vassiliev ◽  
V. Ustinov
Keyword(s):  
Rare Earth ◽  
Pair Breaking ◽  
Breaking Effect ◽  
Doped Manganites ◽  
Magnetic Pair ◽  
Rare Earth Doped
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