Browse
Submit Data
Databases
API
Help

Dataset Information

23 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

High-temperature superconductor of sodalite-like clathrate hafnium hexahydride.

ABSTRACT: Hafnium hydrogen compounds have recently become the vibrant materials for structural prediction at high pressure, from their high potential candidate for high-temperature superconductors. In this work, we predict [Formula: see text] by exploiting the evolutionary searching. A high-pressure phase adopts a sodalite-like clathrate structure, showing the body-centered cubic structure with a space group of [Formula: see text]. The first-principles calculations have been used, including the zero-point energy, to investigate the probable structures up to 600 GPa, and find that the [Formula: see text] structure is thermodynamically and dynamically stable. This remarkable result of the [Formula: see text] structure shows the van Hove singularity at the Fermi level by determining the density of states. We calculate a superconducting transition temperature ([Formula: see text]) using Allen-Dynes equation and demonstrated that it exhibits superconductivity under high pressure with relatively high-[Formula: see text] of 132 K.

SUBMITTER: Tsuppayakorn-Aek P

PROVIDER: S-EPMC8361170 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Superconductive sodalite-like clathrate calcium hydride at high pressures.

Project description:Hydrogen-rich compounds hold promise as high-temperature superconductors under high pressures. Recent theoretical hydride structures on achieving high-pressure superconductivity are composed mainly of H(2) fragments. Through a systematic investigation of Ca hydrides with different hydrogen contents using particle-swam optimization structural search, we show that in the stoichiometry CaH(6) a body-centered cubic structure with hydrogen that forms unusual "sodalite" cages containing enclathrated Ca stabilizes above pressure 150 GPa. The stability of this structure is derived from the acceptance by two H(2) of electrons donated by Ca forming an "H(4)" unit as the building block in the construction of the three-dimensional sodalite cage. This unique structure has a partial occupation of the degenerated orbitals at the zone center. The resultant dynamic Jahn-Teller effect helps to enhance electron-phonon coupling and leads to superconductivity of CaH(6). A superconducting critical temperature (T(c)) of 220-235 K at 150 GPa obtained from the solution of the Eliashberg equations is the highest among all hydrides studied thus far.

| S-EPMC3340045 | biostudies-literature

In-Cage Interactions in the Clathrate Superconductor Sr8 Si46.

Project description:The clathrate?I superconductor Sr8 Si46 is obtained under high-pressure high-temperature conditions, at 5?GPa and temperatures in the range of 1273 to 1373?K. At ambient pressure, the compound decomposes upon heating at T=796(5)?K into Si and SrSi2 . The crystal structure of the clathrate is isotypic to that of Na8 Si46 . Chemical bonding analysis reveals conventional covalent bonding within the silicon network as well as additional multi-atomic interactions between Sr and Si within the framework cages. Physical measurements indicate a bulk BCS type?II superconducting state below Tc =3.8(3)?K.

| S-EPMC7004181 | biostudies-literature

Persistent-mode high-temperature superconductor shim coils: A design concept and experimental results of a prototype Z1 high-temperature superconductor shim.

Project description:Design, fabrication, and test results of a type persistent-mode high-temperature superconductor (HTS) shim coil are presented. A prototype Z1 rectangle-loop shim, cut from 46-mm wide Y-Ba-Cu-O tape manufactured by AMSC, was fabricated and tested at 77 K. The HTS shim, much thinner than the conventional NbTi shim, is placed inside the main magnet and immune to its diamagnetic wall effects. Combined with the >12-T and >10-K operation capability, the HTS shim offers a versatile design option for nuclear magnetic resonance (NMR) magnets, liquid-helium-free as well as conventional, and is particularly attractive in the next generation NMR magnets.

| S-EPMC3745473 | biostudies-other

Extent of Fermi-surface reconstruction in the high-temperature superconductor HgBa2CuO4+?.

Project description:High magnetic fields have revealed a surprisingly small Fermi surface in underdoped cuprates, possibly resulting from Fermi-surface reconstruction due to an order parameter that breaks translational symmetry of the crystal lattice. A crucial issue concerns the doping extent of such a state and its relationship to the principal pseudogap and superconducting phases. We employ pulsed magnetic-field measurements on the cuprate [Formula: see text]Cu[Formula: see text] to identify signatures of Fermi-surface reconstruction from a sign change of the Hall effect and a peak in the temperature-dependent planar resistivity. We trace the termination of Fermi-surface reconstruction to two hole concentrations where the superconducting upper critical fields are found to be enhanced. One of these points is associated with the pseudogap endpoint near optimal doping. These results connect the Fermi-surface reconstruction to both superconductivity and the pseudogap phenomena.

| S-EPMC7211972 | biostudies-literature

Stimulated emission of Cooper pairs in a high-temperature cuprate superconductor.

Project description:The concept of stimulated emission of bosons has played an important role in modern science and technology, and constitutes the working principle for lasers. In a stimulated emission process, an incoming photon enhances the probability that an excited atomic state will transition to a lower energy state and generate a second photon of the same energy. It is expected, but not experimentally shown, that stimulated emission contributes significantly to the zero resistance current in a superconductor by enhancing the probability that scattered Cooper pairs will return to the macroscopically occupied condensate instead of entering any other state. Here, we use time- and angle-resolved photoemission spectroscopy to study the initial rise of the non-equilibrium quasiparticle population in a Bi2Sr2CaCu2O8+? cuprate superconductor induced by an ultrashort laser pulse. Our finding reveals significantly slower buildup of quasiparticles in the superconducting state than in the normal state. The slower buildup only occurs when the pump pulse is too weak to deplete the superconducting condensate, and for cuts inside the Fermi arc region. We propose this is a manifestation of stimulated recombination of broken Cooper pairs, and signals an important momentum space dichotomy in the formation of Cooper pairs inside and outside the Fermi arc region.

| S-EPMC4929572 | biostudies-literature

Interaction-induced singular Fermi surface in a high-temperature oxypnictide superconductor.

Project description:In the family of iron-based superconductors, LaFeAsO-type materials possess the simplest electronic structure due to their pronounced two-dimensionality. And yet they host superconductivity with the highest transition temperature Tc ≈ 55K. Early theoretical predictions of their electronic structure revealed multiple large circular portions of the Fermi surface with a very good geometrical overlap (nesting), believed to enhance the pairing interaction and thus superconductivity. The prevalence of such large circular features in the Fermi surface has since been associated with many other iron-based compounds and has grown to be generally accepted in the field. In this work we show that a prototypical compound of the 1111-type, SmFe(0.92)Co(0.08)AsO , is at odds with this description and possesses a distinctly different Fermi surface, which consists of two singular constructs formed by the edges of several bands, pulled to the Fermi level from the depths of the theoretically predicted band structure by strong electronic interactions. Such singularities dramatically affect the low-energy electronic properties of the material, including superconductivity. We further argue that occurrence of these singularities correlates with the maximum superconducting transition temperature attainable in each material class over the entire family of iron-based superconductors.

| S-EPMC4441009 | biostudies-literature

High pressure effects revisited for the cuprate superconductor family with highest critical temperature.

Project description:How to enhance the superconducting critical temperature (Tc) has been a primary issue since the discovery of superconductivity. The highest Tc reported so far is 166 K in HgBa2Ca2Cu3O8+δ (Hg1223) at high pressure of 23 GPa, as determined with the reduction onset, but not zero, of resistivity. To clarify the possible condition of the real maximum Tc, it is worth revisiting the effects of pressure on Tc in the highest Tc family. Here we report a systematic study of the pressure dependence of Tc in HgBa2CaCu2O6+δ (Hg1212) and Hg1223 with the doping level from underdoped to overdoped. The Tc with zero resistivity is probed with a cubic-anvil-type apparatus that can produce hydrostatic pressures. Variation, not only increase but also decrease, of Tc in Hg1212 and Hg1223 with pressure strongly depends on the initial doping levels. In particular, we confirm a maximum Tc of 153 K at 22 GPa in slightly underdoped Hg1223.

| S-EPMC4686855 | biostudies-literature

Suppression of the antiferromagnetic pseudogap in the electron-doped high-temperature superconductor by protect annealing.

Project description:In the hole-doped cuprates, a small number of carriers suppresses antiferromagnetism and induces superconductivity. In the electron-doped cuprates, on the other hand, superconductivity appears only in a narrow window of high-doped Ce concentration after reduction annealing, and strong antiferromagnetic correlation persists in the superconducting phase. Recently, Pr(1.3-x)La0.7Ce(x)CuO4 (PLCCO) bulk single crystals annealed by a protect annealing method showed a high critical temperature of around 27?K for small Ce content down to 0.05. Here, by angle-resolved photoemission spectroscopy measurements of PLCCO crystals, we observed a sharp quasi-particle peak on the entire Fermi surface without signature of an antiferromagnetic pseudogap unlike all the previous work, indicating a dramatic reduction of antiferromagnetic correlation length and/or of magnetic moments. The superconducting state was found to extend over a wide electron concentration range. The present results fundamentally challenge the long-standing picture on the electronic structure in the electron-doped regime.

| S-EPMC4743021 | biostudies-literature

Enhanced critical current density in the pressure-induced magnetic state of the high-temperature superconductor FeSe.

Project description:We investigate the relation of the critical current density (Jc) and the remarkably increased superconducting transition temperature (Tc) for the FeSe single crystals under pressures up to 2.43 GPa, where the Tc is increased by ~8 K/GPa. The critical current density corresponding to the free flux flow is monotonically enhanced by pressure which is due to the increase in Tc, whereas the depinning critical current density at which the vortex starts to move is more influenced by the pressure-induced magnetic state compared to the increase of Tc. Unlike other high-Tc superconductors, FeSe is not magnetic, but superconducting at ambient pressure. Above a critical pressure where magnetic state is induced and coexists with superconductivity, the depinning Jc abruptly increases even though the increase of the zero-resistivity Tc is negligible, directly indicating that the flux pinning property compared to the Tc enhancement is a more crucial factor for an achievement of a large Jc. In addition, the sharp increase in Jc in the coexisting superconducting phase of FeSe demonstrates that vortices can be effectively trapped by the competing antiferromagnetic order, even though its antagonistic nature against superconductivity is well documented. These results provide new guidance toward technological applications of high-temperature superconductors.

| S-EPMC4637863 | biostudies-literature

Disorder raises the critical temperature of a cuprate superconductor.

Project description:With the discovery of charge-density waves (CDWs) in most members of the cuprate high-temperature superconductors, the interplay between superconductivity and CDWs has become a key point in the debate on the origin of high-temperature superconductivity. Some experiments in cuprates point toward a CDW state competing with superconductivity, but others raise the possibility of a CDW-superconductivity intertwined order or more elusive pair-density waves (PDWs). Here, we have used proton irradiation to induce disorder in crystals of [Formula: see text] and observed a striking 50% increase of [Formula: see text], accompanied by a suppression of the CDWs. This is in sharp contrast with the behavior expected of a d-wave superconductor, for which both magnetic and nonmagnetic defects should suppress [Formula: see text] Our results thus make an unambiguous case for the strong detrimental effect of the CDW on bulk superconductivity in [Formula: see text] Using tunnel diode oscillator (TDO) measurements, we find indications for potential dynamic layer decoupling in a PDW phase. Our results establish irradiation-induced disorder as a particularly relevant tuning parameter for the many families of superconductors with coexisting density waves, which we demonstrate on superconductors such as the dichalcogenides and [Formula: see text].

| S-EPMC6561221 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data