Origin of the critical temperature discontinuity in superconducting sulfur under high pressure

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
M. Monni ◽  
F. Bernardini ◽  
A. Sanna ◽  
G. Profeta ◽  
S. Massidda
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
Temperature Discontinuity

Pressure-induced superconducting CS2H10 with H3S framework

2021 ◽  
Author(s):  
Mingyang Du ◽  
Zihan Zhang ◽  
Tian Cui ◽  
Defang Duan
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Critical Temperature ◽  
Superconducting State ◽  
High Temperature Superconducting ◽  
Critical Temperature Tc ◽  
Important Milestone

The discovery of the high temperature superconducting state in compounds of hydrogen, carbon and sulfur with the critical temperature (Tc) of 288 K at high pressure is an important milestone...

scholarly journals Critical Temperature in Bulk Ultrafine-Grained Superconductors of Nb, V, and Ta Processed by High-Pressure Torsion

2019 ◽  
Vol 60 (7) ◽  
pp. 1367-1376 ◽  
Author(s):  
Terukazu Nishizaki ◽  
Kaveh Edalati ◽  
Seungwon Lee ◽  
Zenji Horita ◽  
Tadahiro Akune ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
High Pressure Torsion ◽  
Ultrafine Grained

scholarly journals Characterization of the superconducting phase in tellurium hydride at high pressure

2019 ◽  
Vol 33 (16) ◽  
pp. 1950169 ◽  
Author(s):  
Tomasz P. Zemła ◽  
Klaudia M. Szczȩśniak ◽  
Adam Z. Kaczmarek ◽  
Svitlana V. Turchuk
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
Strong Coupling ◽  
Superconducting State ◽  
Density Functional ◽  
Superconducting Phase ◽  
Bcs Theory ◽  
Electron Mass ◽  
Eliashberg Equations ◽  
Effective Electron

At present, hydrogen-based compounds constitute one of the most promising classes of materials for applications as phonon-mediated high-temperature superconductors. Herein, the behavior of the superconducting phase in tellurium hydride (HTe) at high pressure (p = 300 GPa) is analyzed in detail, by using the isotropic Migdal–Eliashberg equations. The chosen pressure conditions are considered here as a case study which corresponds to the highest critical temperature value [Formula: see text] in the analyzed material, as determined within recent density functional theory simulations. It is found that the Migdal–Eliashberg formalism, which constitutes a strong-coupling generalization of the Bardeen–Cooper–Schrieffer (BCS) theory, predicts that the critical temperature value ([Formula: see text] K) is higher than previous estimates of the McMillan formula. Further investigations show that the characteristic dimensionless ratios for the thermodynamic critical field, the specific heat for the superconducting state, and the superconducting band gap exceed the limits of the BCS theory. In this context, also the effective electron mass is not equal to the bare electron mass as provided by the BCS theory. On the basis of these findings it is predicted that the strong-coupling and retardation effects play pivotal role in the superconducting phase of HTe at 300 GPa, in agreement with similar theoretical estimates for the sibling hydrogen and hydrogen-based compounds. Hence, it is suggested that the superconducting state in HTe cannot be properly described within the mean-field picture of the BCS theory.

Phase segregation and the effect of high pressure on the electro-transport in Y0.95Pr0.05Ba2Cu3O7-δ single crystals

2014 ◽  
Vol 28 (17) ◽  
pp. 1450142 ◽  
Author(s):  
Ruslan V. Vovk ◽  
Georgij Ya. Khadzhai ◽  
Oleksandr V. Dobrovolskiy
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
Single Crystals ◽  
Oxygen Content ◽  
Pressure Effect ◽  
Phase Segregation ◽  
Sample Volume ◽  
Pressure Derivative ◽  
High Hydrostatic Pressures ◽  
High Pressure Effect

The effect of high hydrostatic pressures of up to 17 kbar on the basal ab-plane conductivity of lightly praseodymium-doped (x ≈ 0.05) Y 1-x Pr x Ba 2 Cu 3 O 7-δ single crystals with unidirectional twin boundaries (TBs) is investigated. It is observed that the application of a high pressure leads to a doubling of the pressure derivative value dTc/dP for Pr -doped samples compared to non-doped YBa 2 Cu 3 O 7-δ samples with optimal oxygen content. Possible mechanisms of the high pressure effect on the critical temperature Tc and the phase segregation in the sample volume are discussed.

scholarly journals Superhard Superconductor Composites Obtained by Sintering of Diamond, c-BN and C60 Powders with Superconductors

2006 ◽  
Vol 61 (12) ◽  
pp. 1541-1546 ◽  
Author(s):  
Gennadi A. Dubitsky ◽  
Vladimir D. Blank ◽  
Sergei G. Buga ◽  
Elena E. Semenova ◽  
Nadejda R. Serebryanaya ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Critical Temperature ◽  
Boron Nitride ◽  
Synthetic Diamond ◽  
Cubic Boron Nitride ◽  
High Pressure High Temperature ◽  
Diamond Powders

Superhard superconducting samples with a critical temperature of TC = 10.5 - 12.6 K were obtained by high-pressure / high-temperature sintering of synthetic diamond powders coated with a niobium film and in 50% - 50% composition with superhard C60 fullerene. Superhard superconductors with TC = 9.3 K were obtained when diamond and molybdenum powders were sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with TC = 36.1 - 37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.

Estimation of the superconducting parameters for silane at high pressure

2014 ◽  
Vol 28 (07) ◽  
pp. 1450052 ◽  
Author(s):  
A. P. Durajski ◽  
R. Szczȩśniak
Keyword(s):  
High Pressure ◽  
Free Energy ◽  
Critical Temperature ◽  
Normal State ◽  
Energy Difference ◽  
Free Energy Difference ◽  
Specific Heat Jump ◽  
Thermodynamic Critical Field ◽  
Coulomb Pseudopotential ◽  
Superconducting Parameters

The properties of the superconducting state in the Cmca phase of silane ( SiH4 ) at the pressure of 250 GPa have been considered. In particular, the critical temperature (TC), the free energy difference between the superconducting and normal state (ΔF ≡ FS - FN), the thermodynamic critical field (HC) and the specific heat jump (ΔC ≡ CS - CN) have been determined. It has been shown that the dimensionless ratios: [Formula: see text] and RC ≡ ΔC(TC)/CN(TC) assume the values: RH(μ⋆) ∈ 〈0.147, 0.154〉 and RC(μ⋆) ∈ 〈2.20, 1.79〉, where the symbol μ⋆ denotes the Coulomb pseudopotential and μ⋆∈ 〈0.1, 0.3〉.

HIGH PRESSURE SYNTHESIS AND CHARACTERIZATION OF YSr2Cu3Ow

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2658-2663 ◽  
Author(s):  
E. GILIOLI ◽  
A. GAUZZI ◽  
T. BESAGNI ◽  
F. LICCI ◽  
M. MAREZIO ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
Neutron Diffraction ◽  
Diffraction Data ◽  
Structural Characteristics ◽  
Normal Pressure ◽  
Synthesis And Characterization ◽  
Neutron Diffraction Data ◽  
Pressure Synthesis

We report the synthesis under pressure, the critical temperature and the structural characteristics of YSr 2 Cu 3 O w . The compound does not form at normal pressure, but, once formed, can be retained at normal pressure in a metastable state. The synthesis was carried out in a multi-anvil apparatus at 30 kBars and 1050°C. The as-prepared sample was found to become superconductor with a Tc of ≈63 K. Tc increased up to ≈70 K after annealing in oxygen at 290°C. The refinement of the neutron diffraction data indicated that the as prepared YSr 2 Cu 3 O w is tetragonal (a=3.7855 Å and c=11.386 Å) and the oxygen content, w , is ≈ 6.84.

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