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Related papers: Metallic Hydrogen: Experiments on Metastability

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\'Eliashberg theory, being generalized to the case of the electron-phonon (EP) systems with the not constant density of electronic states, as well as to the frequency behavior of the renormalization of both the electron mass and the…

Superconductivity · Physics 2016-10-11 Nikolay Kudryashov , Alexander Kutukov , Evgeny Mazur

The electrical resistance of detonation nano-diamond powders was measured from liquid nitrogen temperature to room temperature and in relative humidity environments from around 10% to 100%. After sample exposures of several hours at 100%…

Materials Science · Physics 2018-01-12 B. de Mayo

The high-pressure melting curves of metals provide simple and useful tests for theories of melting, as well as important constraints for the modeling of planetary interiors. Here, we present an experimental technique that reveals the latent…

It has been suggested that hydrogen may metallise at lower pressures if it is ``precompressed''. Here we introduce a search strategy for predicting high-pressure structures and apply it to silane using first-principles electronic structure…

Materials Science · Physics 2009-11-11 Chris J. Pickard , R. J. Needs

A recent experimental study of the metallization of hydrogen tracked the direct band gap and vibron frequency via infrared measurements up to ~425 GPa [P. Loubeyre et al., Nature 577, 631 (2020)]. Above this pressure, the direct gap has a…

Materials Science · Physics 2020-10-22 Mehmet Dogan , Sehoon Oh , Marvin L. Cohen

Noble metals adopt close-packed structures at ambient pressure and rarely undergo structural transformation at high pressures. Platinum (Pt), in particular, is normally considered to be unreactive and is therefore not expected to form…

Superconductivity · Physics 2015-03-19 Duck Young Kim , Ralph H. Scheicher , Chris J. Pickard , R. J. Needs , R. Ahuja

The low-pressure stabilization of superconducting hydrides with high critical temperatures ($T_c$s) remains a significant challenge, and experimentally verified superconducting hydrides are generally constrained to a limited number of…

In an experiment in a diamond anvil cell utilizing helium pressure medium, yttrium metal displays a superconducting transition temperature which increases monotonically from Tc ? 3.5 K at 30 GPa to 17 K at 89.3 GPa, one of the highest…

Superconductivity · Physics 2009-11-11 J. J. Hamlin , V. G. Tissen , J. S. Schilling

In recent years there has been intense experimental activity to observe solid metallic hydrogen. Wigner and Huntington predicted that under extreme pressures insulating molecular hydrogen would dissociate and transition to atomic metallic…

Other Condensed Matter · Physics 2016-05-19 Ranga P. Dias , Ori Noked , Isaac F. Silvera

Silane (SiH4) is found to (partially) decompose at pressures above 50 GPa at room temperature into pure Si and H2. The released hydrogen reacts with surrounding metals in the diamond anvil cell to form metal hydrides. A formation of rhenium…

The phase diagram of oxygen is investigated for pressures from 50 to 130~GPa and temperatures up 1200 K using first principles theory. A metallic molecular structure with the $P6_3/mmc$ symmetry ($\eta^{'}$ phase) is determined to be…

Computational Physics · Physics 2019-02-19 S. F. Elatresh , S. A. Bonev

Hydrogen exhibits unusual behaviors at megabar pressures, with consequences for planetary science, condensed matter physics and materials science. Experiments at such extreme conditions are challenging, often resulting in hard-to-interpret…

Materials Science · Physics 2022-01-05 Bingqing Cheng , Guglielmo Mazzola , Michele Ceriotti

By employing first-principles metadynamics simulations, we explore the 300 K structures of solid hydrogen over the pressure range 150-300 GPa. At 200 GPa, we find the ambient-pressure disordered hexagonal close-packed (hcp) phase transited…

Materials Science · Physics 2012-08-16 Hanyu Liu , Li Zhu , Wenwen Cui , Yanming Ma

We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder…

The paper determines the thermodynamic parameters of the superconducting state in the metallic atomic hydrogen under the pressure at $1$ TPa, $1.5$ TPa, and $2.5$ TPa. The calculations were conducted in the framework of the Eliashberg…

Superconductivity · Physics 2016-07-20 A. M. Duda , R. Szczęśniak , M. A. Sowińska , A. H. Kosiacka

The insulator-to-metal transition in solid helium at high pressure is studied with first-principles simulations. Diffusion quantum Monte Carlo (DMC) calculations predict that the band gap closes at a density of 21.3 g/cc and a pressure of…

Computational Physics · Physics 2008-05-30 Saad Antoun Khairallah , Burkhard Militzer

Structural behavior and equation of state of atomic and molecular crystal phases of dense hydrogen at pressures up to 3.5 TPa are systematically investigated with density functional theory. The results indicate that the Vinet EOS model that…

Other Condensed Matter · Physics 2012-03-27 Hua Y. Geng , Hong X. Song , J. F. Li , Q. Wu

The structural, electronic, and spectroscopic properties of a high-pressure phase of methane hydrate (MH-III) are studied by first principles electronic structure calculations. A detailed analysis of the atomic positions suggests that {\it…

Materials Science · Physics 2007-05-23 Toshiaki Iitaka , Toshikazu Ebisuzaki

Being the simplest element with just one electron and proton the electronic structure of the Hydrogen atom is known exactly. However, this does not hold for the complex interplay between them in a solid and in particular not at high…

Materials Science · Physics 2014-06-23 Sam Azadi , Thomas D. Kühne

The study of the high pressure phase diagram of hydrogen has continued with renewed effort for about one century as it remains a fundamental challenge for experimental and theoretical techniques. Here we employ an efficient molecular…

Chemical Physics · Physics 2014-04-23 Guglielmo Mazzola , Seiji Yunoki , Sandro Sorella
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