High-temperature superconductivity in transition metallic hydrides MH11 (M = Mo, W, Nb, and Ta) under high pressure

2021 ◽  
Vol 23 (11) ◽  
pp. 6717-6724
Author(s):  
Mingyang Du ◽  
Zihan Zhang ◽  
Hao Song ◽  
Hongyu Yu ◽  
Tian Cui ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Transition Temperature ◽  
Critical Temperature ◽  
Superconducting Transition Temperature ◽  
High Temperature Superconductivity ◽  
Superconducting Transition ◽  
Optical Phonons ◽  
Acoustic Phonons ◽  
Acoustic Modes

The contribution of optical and acoustic modes to the superconducting transition temperature. The calculated EPC parameter λ, critical temperature (Tc), critical temperature caused by the interaction of electrons with optical phonons (T0c) and acoustic phonons (Tacc).

PHONON SPECTRUM AND THE ELASTIC CONSTANTS OF HIGH TcBa2YCu3O7

1988 ◽  
Vol 02 (06) ◽  
pp. 811-817 ◽  
Author(s):  
H.C. GUPTA
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Elastic Constants ◽  
Phonon Spectrum ◽  
High Temperature Superconductivity ◽  
Force Model ◽  
Superconducting Transition ◽  
Optical Phonons ◽  
Infra Red ◽  
Zone Centre

The phonon spectrum and the elastic constants of high superconducting transition temperature compound Ba2YCu3O7 have been investigated in both the tetragonal and the orthorhombic phases using an angular force model. The zone centre phonons agree well with the Raman and the infra-red measurements in the case of tetragonal phase as compared to the orthorhombic one. The acoustical phonons exhibit phonon anomalies in both the tetragonal and the orthorhombic structures. Number of optical phonons do not show dispersion in [ooq] direction indicating strong 2-dimensional features. The relevance of the phonons to the high temperature superconductivity is discussed. The elastic constants do not indicate anisotropy in either of the tetragonal or the orthorhombic phases.

THE EVOLUTION OF HTS: Tc-EXPERIMENT PERSPECTIVES

2010 ◽  
Vol 24 (20n21) ◽  
pp. 4102-4149 ◽  
Author(s):  
C. W. Chu
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Heavy Fermion ◽  
Room Temperature ◽  
High Temperature Superconductivity ◽  
Superconducting Transition ◽  
Two Systems ◽  
Heavy Fermion Superconductors

The rise of the superconducting transition temperature Tc has been reviewed in three major superconducting systems: the cuprate, the Fe -pnictide and the heavy fermion. While the first two systems display high Tc s , heavy fermion superconductors show low Tc but embody many crucial features found in the others. The prospect of future superconductors with higher Tc, preferably close to room temperature, is also discussed. Those interested in the detailed physics of high temperature superconductivity are referred to the article by E. Abrahams in the next chapter of this book and reviews published elsewhere.

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.

scholarly journals High temperature superconductivity in sulfur hydride under ultrahigh pressure: A complex superconducting phase beyond conventional BCS

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Annette Bussmann-Holder ◽  
Jürgen Köhler ◽  
M.-H. Whangbo ◽  
Antonio Bianconi ◽  
Arndt Simon
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Transition Temperature ◽  
Hydrogen Bonds ◽  
Pressure Dependence ◽  
High Temperature Superconductivity ◽  
Superconducting Phase ◽  
Ultrahigh Pressure ◽  
Phonon Modes ◽  
Interband Coupling

AbstractThe recent report of superconductivity under high pressure at the record transition temperature of Tc =203 K in pressurized H2S has been identified as conventional in view of the observation of an isotope effect upon deuteration. Here it is demonstrated that conventional theories of superconductivity in the sense of BCS or Eliashberg formalisms cannot account for the pressure dependence of the isotope coefficient. The only way out of the dilemma is a multi-band approach of superconductivity where already small interband coupling suffices to achieve the high values of Tc together with the anomalous pressure dependent isotope coefficient. In addition, it is shown that anharmonicity of the hydrogen bonds vanishes under pressure whereas anharmonic phonon modes related to sulfur are still active.

Volume dependence of the superconducting transition temperature for the high-temperature superconductorHgBa2Ca2−xPbxCu3O8+δ

1994 ◽  
Vol 50 (18) ◽  
pp. 13778-13785 ◽  
Author(s):  
Charles C. Kim ◽  
A. R. Drews ◽  
E. F. Skelton ◽  
S. B. Qadri ◽  
M. S. Osofsky ◽  
...  
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Volume Dependence

Simulation of Structural Parameters and Superconducting Transition Temperature of MgB2 under Pressure

2005 ◽  
Vol 475-479 ◽  
pp. 3319-3322
Author(s):  
Yang Shao ◽  
X. Zhang ◽  
Fu Ling Tang
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Transition Temperature ◽  
Superconducting Transition Temperature ◽  
Pressure Effect ◽  
Structural Parameters ◽  
Experimental Results ◽  
Bcs Theory ◽  
Superconducting Transition ◽  
Potential Parameters

We successfully developed the potential parameters for simulation of MgB2. With these potential parameters, we calculate the lattice parameters and volume variations with pressure up to 240GPa. All these results agree well with experimental data under 40GPa and provide reasonable tendencies from 40GPa to 240GPa. By employing the McMillan expression, it is found that the lattice stiffening dominants the behavior of Tc under pressure in the scope of BCS theory. Using our calculated Grüneisen parameter G g , the simulated pressure effect on Tc accords well with experimental results. Our result shows that the Tc of MgB2 can be destroyed by high pressure.

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.

Ultra-Low-Field Squid Magnetic Measurements on High Temperature Ceramic YBaCuO Superconductors

1987 ◽  
Vol 99 ◽  
Author(s):  
D. C. Cronemeyer ◽  
A. P. Malozemoff ◽  
T. R. Mcguire
Keyword(s):  
High Temperature ◽  
Transition Temperature ◽  
Ceramic Sample ◽  
Superconducting Transition Temperature ◽  
Magnetic Measurements ◽  
Zero Field ◽  
Superconducting Transition ◽  
Temperature Range ◽  
Low Field ◽  
The Difference

ABSTRACTWe report ultra-low-field (5 mOe - 1 Oe) magnetic measurements on a ceramic sample of YBaCuO. A positive remanent moment is observed which accurately equals the difference of the field-cooled and zero-field-cooled moments throughout the temperature range. At higher fields this relationship breaks down. A reversible region is observed near the superconducting transition temperature which is independent of field. These results are discussed in the context of recent models.

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