High Pressure Stabilization and Emergent Forms of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>PbH</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>

Zaleski‐Ejgierd, Patryk; Hoffmann, Roald; Ashcroft, N. W.

doi:10.1103/physrevlett.107.037002

Cited by 63 publications

(42 citation statements)

References 25 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this structure can not be confirmed as a unique solution given the variety of structures energetically competitive and very similar to the simple cubic structure at that pressure. They are also associated with small hydrogen displacements in contrast to the proposed nearly isoenthalpic phases in heavy metal hydrides with mobile and structurally quite different layers of hydrogen molecules [26]. Moreover, in spite of the similar common metallic subarray, no reminiscent electride behavior as reported in Ref.…”

Section: Fig 3 (Color Online) (A) Calculated Enthalpies Of Formatiomentioning

confidence: 66%

High-Pressure Synthesis and Characterization of Iridium Trihydride

Scheler

Marqués

Konôpková³

et al. 2013

Phys. Rev. Lett.

View full text Add to dashboard Cite

We have performed in situ synchrotron x-ray diffraction studies of the iridium-hydrogen system up to 125 GPa. At 55 GPa, a phase transition in the metal lattice from the fcc to a distorted simple cubic phase is observed. The new phase is characterized by a drastically increased volume per metal atom, indicating the formation of a metal hydride, and substantially decreased bulk modulus of 190 GPa (383 GPa for pure Ir). Ab initio calculations show that the hydrogen atoms occupy the face-centered positions in the metal matrix, making this the first known noninterstitial noble metal hydride and, with a stoichiometry of IrH 3 , the one with the highest volumetric hydrogen content. Computations also reveal that several energetically competing phases exist, which can all be seen as having distorted simple cubic lattices. Slow kinetics during decomposition at pressures as low as 6 GPa suggest that this material is metastable at ambient pressure and low temperatures.

show abstract

Section: Fig 3 (Color Online) (A) Calculated Enthalpies Of Formatiomentioning

confidence: 66%

High-Pressure Synthesis and Characterization of Iridium Trihydride

Scheler

Marqués

Konôpková³

et al. 2013

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…For instance, one might reason from the fact that Y (54) itself has a distorted fcc structure that it may be possible to produce sodalite-like YH 10 at a metal-hydrogen interface. The exploration, theoretical and experimental, of high hydrides of heavy metals is thus a promising field (55)(56)(57)(58).…”

Section: Discussionmentioning

confidence: 99%

Potential high- T _c superconducting lanthanum and yttrium hydrides at high pressure

Liu

Naumov

Hoffmann

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

758

467

View full text Add to dashboard Cite

A systematic structure search in the La-H and Y-H systems under pressure reveals some hydrogen-rich structures with intriguing electronic properties. For example, LaH 10 is found to adopt a sodalite-like face-centered cubic (fcc) structure, stable above 200 GPa, and LaH 8 a C2/m space group structure. Phonon calculations indicate both are dynamically stable; electron phonon calculations coupled to Bardeen-Cooper-Schrieffer (BCS) arguments indicate they might be high-T c superconductors. In particular, the superconducting transition temperature T c calculated for LaH 10 is 274-286 K at 210 GPa. Similar calculations for the Y-H system predict stability of the sodalite-like fcc YH 10 and a T c above room temperature, reaching 305-326 K at 250 GPa. The study suggests that dense hydrides consisting of these and related hydrogen polyhedral networks may represent new classes of potential very hightemperature superconductors.high pressure | superconductivity | hydrides | structure search E xtending his original predictions of very high-temperature superconductivity of high-pressure metallic hydrogen (1), Ashcroft later proposed that hydrogen-rich materials containing main group elements might exhibit superconductivity at lower pressures, as the hydrogen in these structures may be considered "chemically precompressed" (2). These proposals, which were based on the Bardeen-Cooper-Schrieffer (BCS) (3) phononmediated theory of superconductivity, have motivated many theoretical and experimental efforts in the search for hightemperature superconductivity in hydrides at elevated pressures (4-10). Theory has predicted the stability of a variety of dense hydride structures for which BCS arguments give superconducting transition temperatures, T c s, that are very high (11)(12)(13)(14)(15)(16)(17)(18).In recent times, compression of hydrogen sulfides has provided a new incentive in hydride superconductivity, one in which theory played an important role. First, theoretical calculations predicted H 2 S to have a T c of ∼80 K at pressures above 100 GPa (19). Compression of H 2 S led to the striking discovery of a superconducting material with a T c of 203 K at 200 GPa (20). Moreover, the critical temperature exhibits a pronounced isotope shift consistent with BCS theory. It was proposed that the superconducting phase is not stoichiometric H 2 S but SH 3 , with a calculated T c of 194 K at 200 GPa including anharmonic effects (21,22). A subsequent experiment (23) suggested that the superconducting phase is cubic SH 3 , in agreement with a theoretical study that gave T c = 204 K within the harmonic approximation (24). Compression of another hydride, PH 3 , was reported to reach a T c of ∼100 K at high pressures (25). Subsequent theoretical calculations predicted possible structures and calculated T c s close to the experimental results (26-28). The experimental picture for these materials remains not entirely clear, and the synthesis of the superconducting phases, which has been reproduced for hydrogen sulfide, is path-dependent (23).Th...

show abstract

“…By 140 GPa (V/V 0 = 0.21) the coordination of tin and hydrogen increases and the slabs disappear, as judged from the optimized structures. has been seen theoretically, in silane [4] and germane, [7] and just recently, stannane, and plumbane, [21] and Gao and coworkers concluded that segregation is also likely in pressurized stannane at P < 96 GPa. [22] …”

Section: The Question As It Emerges For Snhmentioning

confidence: 99%

Segregation into Layers: A General Problem for Structural Instability under Pressure, Exemplified by SnH₄

2010

Self Cite

View full text Add to dashboard Cite

When a molecular compound is thermodynamically unstable (but kinetically persistent) with respect to the elements, structures that contain segregated layers of the elements may be favored at moderate pressures, as a compromise between the potential stability of novel electronic configurations and decomposition into the elements (or other stable compounds). We use stannane, SnH4, to approach this quite general problem theoretically, since the heat of formation of SnH4 is so positive. Our ground‐state DFT searches for optimal structures begin with slabs formed from 1–4 layers of tin atoms in the β‐Sn and bcc configurations, and also slabs of molecular hydrogen or hydrogen atoms, preserving the overall SnH4 stoichiometry. As argued, segregated layers are an important structural feature in the lower‐ and moderate‐pressure regime (0 and 50 GPa). By 140 GPa (V/V0=0.21) the coordination of tin and hydrogen increases and the slabs disappear, as judged from the optimized structures.

show abstract

High Pressure Stabilization and Emergent Forms ofPbH4

Cited by 63 publications

References 25 publications

High-Pressure Synthesis and Characterization of Iridium Trihydride

High-Pressure Synthesis and Characterization of Iridium Trihydride

Potential high- T _c superconducting lanthanum and yttrium hydrides at high pressure

Segregation into Layers: A General Problem for Structural Instability under Pressure, Exemplified by SnH₄

Contact Info

Product

Resources

About

High Pressure Stabilization and Emergent Forms ofPbH4

Cited by 63 publications

References 25 publications

High-Pressure Synthesis and Characterization of Iridium Trihydride

High-Pressure Synthesis and Characterization of Iridium Trihydride

Potential high- T c superconducting lanthanum and yttrium hydrides at high pressure

Segregation into Layers: A General Problem for Structural Instability under Pressure, Exemplified by SnH4

Contact Info

Product

Resources

About

Potential high- T _c superconducting lanthanum and yttrium hydrides at high pressure

Segregation into Layers: A General Problem for Structural Instability under Pressure, Exemplified by SnH₄