Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Pressure-stabilized superconductive yttrium hydrides.

ABSTRACT: The search for high-temperature superconductors has been focused on compounds containing a large fraction of hydrogen, such as SiH4(H2)2, CaH6 and KH6. Through a systematic investigation of yttrium hydrides at different hydrogen contents using an structure prediction method based on the particle swarm optimization algorithm, we have predicted two new yttrium hydrides (YH4 andYH6), which are stable above 110 GPa. Three types of hydrogen species with increased H contents were found, monatomic H in YH3, monatomic H+molecular "H2" in YH4 and hexagonal "H6" unit in YH6. Interestingly, H atoms in YH6 form sodalite-like cage sublattice with centered Y atom. Electron-phonon calculations revealed the superconductive potential of YH4 and YH6 with estimated transition temperatures (Tc) of 84-95 K and 251-264 K at 120 GPa, respectively. These values are higher than the predicted maximal Tc of 40 K in YH3.

SUBMITTER: Li Y

PROVIDER: S-EPMC4419593 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Anomalous perovskite PbRuO3 stabilized under high pressure.

Project description:Perovskite oxides ABO3 are important materials used as components in electronic devices. The highly compact crystal structure consists of a framework of corner-shared BO6 octahedra enclosing the A-site cations. Because of these structural features, forming a strong bond between A and B cations is highly unlikely and has not been reported in the literature. Here we report a pressure-induced first-order transition in PbRuO3 from a common orthorhombic phase (Pbnm) to an orthorhombic phase (Pbn21) at 32 GPa by using synchrotron X-ray diffraction. This transition has been further verified with resistivity measurements and Raman spectra under high pressure. In contrast to most well-studied perovskites under high pressure, the Pbn21 phase of PbRuO3 stabilized at high pressure is a polar perovskite. More interestingly, the Pbn21 phase has the most distorted octahedra and a shortest Pb-Ru bond length relative to the average Pb-Ru bond length that has ever been reported in a perovskite structure. We have also simulated the behavior of the PbRuO3 perovskite under high pressure by first principles calculations. The calculated critical pressure for the phase transition and evolution of lattice parameters under pressure match the experimental results quantitatively. Our calculations also reveal that the hybridization between a Ru:t2g orbital and an sp hybrid on Pb increases dramatically in the Pbnm phase under pressure. This pressure-induced change destabilizes the Pbnm phase to give a phase transition to the Pbn21 phase where electrons in the overlapping orbitals form bonding and antibonding states along the shortest Ru-Pb direction at P > Pc.

| S-EPMC3864321 | biostudies-literature

Hexacoordinated nitrogen(V) stabilized by high pressure.

Project description:In all of its known connections nitrogen retains a valence shell electron count of eight therefore satisfying the golden rule of chemistry - the octet rule. Despite the diversity of nitrogen chemistry (with oxidation states ranging from + 5 to -3), and despite numerous efforts, compounds containing nitrogen with a higher electron count (hypervalent nitrogen) remain elusive and are yet to be synthesized. One possible route leading to nitrogen's hypervalency is the formation of a chemical moiety containing pentavalent nitrogen atoms coordinated by more than four substituents. Here, we present theoretical evidence that a salt containing hexacoordinated nitrogen(V), in the form of an NF6- anion, could be synthesized at a modest pressure of 40 GPa (=400 kbar) via spontaneous oxidation of NF3 by F2. Our results indicate that the synthesis of a new class of compounds containing hypervalent nitrogen is within reach of current high-pressure experimental techniques.

| S-EPMC5093683 | biostudies-literature

Superconductivity up to 243 K in the yttrium-hydrogen system under high pressure.

Project description:The discovery of superconducting H3S with a critical temperature Tc∼200 K opened a door to room temperature superconductivity and stimulated further extensive studies of hydrogen-rich compounds stabilized by high pressure. Here, we report a comprehensive study of the yttrium-hydrogen system with the highest predicted Tcs among binary compounds and discuss the contradictions between different theoretical calculations and experimental data. We synthesized yttrium hydrides with the compositions of YH3, YH4, YH6 and YH9 in a diamond anvil cell and studied their crystal structures, electrical and magnetic transport properties, and isotopic effects. We found superconductivity in the Im-3m YH6 and P63/mmc YH9 phases with maximal Tcs of ∼220 K at 183 GPa and ∼243 K at 201 GPa, respectively. Fm-3m YH10 with the highest predicted Tc > 300 K was not observed in our experiments, and instead, YH9 was found to be the hydrogen-richest yttrium hydride in the studied pressure and temperature range up to record 410 GPa and 2250 K.

| S-EPMC8379216 | biostudies-literature

Diverse ruthenium nitrides stabilized under pressure: a theoretical prediction.

Project description:First-principles calculations were performed to understand the structural stability, synthesis routes, mechanical and electronic properties of diverse ruthenium nitrides. RuN with a new I-4m2 symmetry stabilized by pressure is found to be energetically preferred over the experimental NaCl-type and ZnS-type ones. The Pnnm-RuN2 is found to be stable above 1.1 GPa, in agreement with the experimental results. Specifically, new stoichiometries like RuN3 and RuN4 are proposed firstly to be thermodynamically stable, and the dynamical and mechanical stabilities of the newly predicted structures have been verified by checking their phonon spectra and elastic constants. A phase transition from P4/mmm-RuN4 to C2/c-RuN4 is also uncovered at 23.0 GPa. Drawn from bonding and band structure analysis, P4/mmm-RuN4 exhibits semi-metal-like behavior and becomes a semiconductor for the high-pressure C2/c-RuN4 phase. Meanwhile the P21/c-RuN3 shows metallic feature. Highly directional covalent N-N and Ru-N bonds are formed and dominating in N-enriched Ru nitrides, making them promising hard materials.

| S-EPMC5024155 | biostudies-literature

High-Pressure Polymorphs Nucleated and Stabilized by Rational Doping under Ambient Conditions.

Project description:High-pressure polymorphs can be obtained and stabilized at ambient pressure by utilizing dopants with more voluminous molecules, inducing internal strain in the structures. This effect has been confirmed for doped resorcinol and imidazole derivatives by nucleating and stabilizing their high-pressure phases under ambient conditions. The dopant molecular volume and concentration, as well as the bulk modulus of the polymorph in the binary system, are related to the stability region in the single-component phase diagram. High-pressure isothermal and isochoric recrystallizations yielded pure single crystals of resorcinol ε above 0.20 GPa and a new polymorph ζ above 0.70 GPa. These recrystallizations of pure resorcinol revealed within 1 GPa of the p-T phase diagram the boundaries and the stability regions of four resorcinol polymorphs α, β, ε, and ζ, contrary to the compression experiments on ambient-pressure polymorphs α and β, when the high-pressure phases were hidden behind the wide hysteresis extending to nearly 5 GPa. The hysteresis, originating from the H-bonding networks, hinders the formation of polymorphs ε and ζ when polymorphs α and β are compressed without melting or dissolving the crystals. Polymorph ζ is the only known resorcinol structure built of hydrogen-bonded layers.

| S-EPMC8559611 | biostudies-literature

Close identity of a pressure-stabilized intermediate with a kinetic intermediate in protein folding.

Project description:Atomic detailed structural study of a transiently existing folding intermediate is severely limited because of its short life. In ubiquitin, we found that a pressure-stabilized equilibrium conformer shares a common structural feature with the proline-trapped kinetic intermediate found in a pulse-labeling (1)H(2)H exchange NMR study [Briggs, M. S. & Roder, H. (1992) Proc. Natl. Acad. Sci. USA 89, 2017-2021]. The conformer is locally unfolded in the entire segment from residues 33 to 42 and in C-terminal residues 70-76. The close structural identity of an equilibrium intermediate stabilized under pressure with a transiently observed folding intermediate is likely to be general in terms of a folding funnel common to both experiments.

| S-EPMC152264 | biostudies-literature

Pressure-stabilized divalent ozonide CaO<sub>3</sub> and its impact on Earth's oxygen cycles.

Project description:High pressure can drastically alter chemical bonding and produce exotic compounds that defy conventional wisdom. Especially significant are compounds pertaining to oxygen cycles inside Earth, which hold key to understanding major geological events that impact the environment essential to life on Earth. Here we report the discovery of pressure-stabilized divalent ozonide CaO3 crystal that exhibits intriguing bonding and oxidation states with profound geological implications. Our computational study identifies a crystalline phase of CaO3 by reaction of CaO and O2 at high pressure and high temperature conditions; ensuing experiments synthesize this rare compound under compression in a diamond anvil cell with laser heating. High-pressure x-ray diffraction data show that CaO3 crystal forms at 35 GPa and persists down to 20 GPa on decompression. Analysis of charge states reveals a formal oxidation state of -2 for ozone anions in CaO3. These findings unravel the ozonide chemistry at high pressure and offer insights for elucidating prominent seismic anomalies and oxygen cycles in Earth's interior. We further predict multiple reactions producing CaO3 by geologically abundant mineral precursors at various depths in Earth's mantle.

| S-EPMC7499259 | biostudies-literature

Yttrium ethyl-enediammonium squarate tetra-hydrate.

Project description:The title compound, {(C(2)H(10)N(2))(1.5)[Y(C(4)O(4))(3)(H(2)O)(4)]}(n) {system-atic name: catena-poly[sesqui(ethyl-enediammonium) [[tetra-aquabis-(squarato-?O)yttrium(III)]-?-squarato-?(2)O:O']]}, was synthesized by slow evaporation of an acid solution. The asymetric unit contains one yttrium cation in an anti-prismatic environnement, three squarate groups, one and a half protonated ethyl-enediamine mol-ecules and four water mol-ecules. YO(8) polyhedra are connected through bis-(mono-dentate) squarates, leading to infinite zigzag chains, in between which are located ammonium groups. A framework of hydrogen bonds between protonated amine N atoms, water mol-ecules and squarate anions ensures the cohesion of the structure.

| S-EPMC3089218 | biostudies-literature

Extrahepatic Applications of Yttrium-90 Radioembolization.

Project description:While initially described and now accepted as treatment for primary and secondary malignancies in the liver, radioembolization therapy has expanded to include treatment for other disease pathologies and other organ systems. Advantages and limitations for these treatments exist and must be compared against more traditional treatments for these processes. This article provides an overview of the current applications for radioembolization outside of the liver, for both malignant and nonmalignant disease.

| S-EPMC8497088 | biostudies-literature

Extensively hydrated but folded: a novel state of globular proteins stabilized at high pressure and low temperature.

Project description:We studied conformational fluctuations of the transcription factor c-Myb R2 subdomain (52 residues with three Trp) at high pressure and low temperature (5°C) using two different spectroscopic methods, Trp fluorescence and (1)H NMR, on its chemically stable mutant C130I (pseudo-wild-type (WT(S))), which has a large internal cavity. As pressure was increased from 3 to 300 MPa, the Trp fluorescence ?(max) of WT(S) shifted from 342 to ?355 nm, clearly showing that the three Trp rings become fully exposed to the polar environment, which usually is taken to indicate that the protein underwent unfolding. In contrast, as pressure was increased from 3 to 300 MPa, the high-field-shifted (1)H NMR signals characteristic of the folded state showed a still higher-field shift, but no significant changes in their intensity. The last result unequivocally shows that the protein remains largely folded at 300 MPa. The apparent discrepancy between the two predictions would only be solved if one were to postulate the existence of an extensively hydrated but folded state in WT(S). Intriguingly, such a state was not found in a cavity-filling mutant of WT(S), C130I/V103L, suggesting that this state is mediated by cavity hydration. The generality and significance of this state in proteins are discussed.

| S-EPMC3260745 | 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