ChemInform Abstract: Anomalous Behavior of the Superconducting Transition Temperature and Width in the Tl-Ba-Ca-Cu-O System in Dependence on the Metal Oxides Concentration.

ChemInform ◽  
2010 ◽  
Vol 29 (50) ◽  
pp. no-no
Author(s):  
V. E. VOLKOV ◽  
J. YU. DANILOV ◽  
L. A. ZHAROVA ◽  
YU. G. KOVALEV ◽  
L. L. ZHIDKOV ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Metal Oxides ◽  
Superconducting Transition Temperature ◽  
Anomalous Behavior ◽  
Superconducting Transition

Effect of He Pressure on the Superconducting Transition Temperatures of Na2CsC60 and (NH3)4Na2CsC60

1994 ◽  
Vol 359 ◽  
Author(s):  
J.E Schirber ◽  
W.R. Bayless ◽  
M.J. Rosseinsky ◽  
O. Zhou ◽  
R.M. Fleming ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Lattice Spacing ◽  
Anomalous Behavior ◽  
Pressure Measurements ◽  
Superconducting Transition ◽  
Substantial Agreement ◽  
Mixed Alkali ◽  
Pressure Medium ◽  
Solid He

ABSTRACTThe Na based mixed alkali doped C60 superconductors show anomalous behavior with respect to the “universal” superconducting transition temperature Tc vs lattice constant ao relation followed by most of the fcc A3C60 superconductors. We have measured dTc/dP for Na2CsC60 and (NH3)4Na2CsC60 using solid He as the pressure medium to ∼ 6 kbar finding dTc/dP equal to −0.88±(0.01) K/kbar and −1.0(±0.1) K/kbar for Na2CsC60 and Na2(NH3)4C60 respectively. Our value for Na2CsC60 differs markedly from that obtained by Mizuki et al of about −1.3 K/kbar. However, using N2 or Ar, we obtain values for dTc/dP in substantial agreement with Mizuki et al who used fluorinert to generate their pressure. This work emphasizes the need for compressibility measurements with the same pressure medium in the appropriate temperature range so that meaningful comparisons can be made between various pressure measurements and models which are based on lattice spacing.

scholarly journals Enhancing Superconductivity of the Nonmagnetic Quasiskutterudites by Atomic Disorder

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5830
Author(s):  
Andrzej Ślebarski ◽  
Maciej M. Maśka
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
High Temperature Superconductors ◽  
Superconducting Phase ◽  
Length Scale ◽  
Superconducting Transition ◽  
Atomic Disorder ◽  
Strong Inhomogeneity ◽  
Related Compounds

We investigated the effect of enhancement of superconducting transition temperature Tc by nonmagnetic atom disorder in the series of filled skutterudite-related compounds (La3M4Sn13, Ca3Rh4Sn13, Y5Rh6Sn18, Lu5Rh6Sn18; M= Co, Ru, Rh), where the atomic disorder is generated by various defects or doping. We have shown that the disorder on the coherence length scale ξ in these nonmagnetic quasiskutterudite superconductors additionally generates a non-homogeneous, high-temperature superconducting phase with Tc⋆>Tc (dilute disorder scenario), while the strong fluctuations of stoichiometry due to increasing doping can rapidly increase the superconducting transition temperature of the sample even to the value of Tc⋆∼2Tc (dense disorder leading to strong inhomogeneity). This phenomenon seems to be characteristic of high-temperature superconductors and superconducting heavy fermions, and recently have received renewed attention. We experimentally documented the stronger lattice stiffening of the inhomogeneous superconducting phase Tc⋆ in respect to the bulk Tc one and proposed a model that explains the Tc⋆>Tc behavior in the series of nonmagnetic skutterudite-related compounds.

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