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Related papers: Helium-iron compounds at terapascal pressures

200 papers

Iron-based superconductors are well-known for their intriguing phase diagrams, which manifest a complex interplay of electronic, magnetic and structural degrees of freedom. Among the phase transitions observed are superconducting, magnetic,…

Superconductivity · Physics 2020-10-28 Elena Gati , Li Xiang , Sergey L. Bud'ko , Paul C. Canfield

We report the XRD and Raman scattering measurements in combination with DFT calculations that reveal the formation of beryllium polyhydride Be4H8(H2)2 by laser heating Be/H2 mixture to above 1700 K at pressures between 5 GPa and 8 GPa. The…

First-principles simulations have been performed to investigate the phase stability of tantalum metal under high pressure and high temperature (HPHT). We searched its low-energy structures globally using our developed multi-algorithm…

Materials Science · Physics 2014-10-31 Zhong-Li Liu , Ling-Cang Cai , Xiu-Lu Zhang , Feng Xi

Helium (He) is the ideal atom to perform tests of ab-initio calculations in two-electron systems that consider all known effects, including quantum-electrodynamics and nuclear-size contributions. Recent state-of-the-art calculations and…

Atomic Physics · Physics 2025-01-07 Gloria Clausen , Kai Gamlin , Josef A. Agner , Hansjürg Schmutz , Frédéric Merkt

Recent predictions of metastable high-temperature hydride superconductors give hope that superconductivity at ambient conditions is within reach. In this work, we predict RbPH$_3$ as a new compound with a superconducting critical…

The thermodynamic stabilities of various phases of the nitrides of the platinum metal elements are systematically studied using density functional theory. It is shown that for the nitrides of Rh, Pd, Ir and Pt two new crystal structures, in…

Materials Science · Physics 2010-09-03 Daniel Åberg , Babak Sadigh , Jonathan Crowhurst , Alexander F. Goncharov

We study different solid phases of Helium-four, by means of Path Integral Monte Carlo simulations based on a recently developed "worm" algorithm. Our study includes simulations that start off from a high-T gas phase, which is then…

Statistical Mechanics · Physics 2009-11-11 M. Boninsegni , N. Prokof'ev , B. Svistunov

We present the first models of Saturn and Jupiter to couple their evolution to both a radiative-atmosphere grid and to high-pressure phase diagrams of hydrogen with helium. The purpose of these models is to quantify the evolutionary effects…

Astrophysics · Physics 2009-11-10 Jonathan J. Fortney , W. B. Hubbard

We map the high-pressure phase diagram of nitrogen hydrate up to 16 GPa at room temperature by combining neutron diffraction, Raman spectroscopy, and crystal structure prediction. We reveal a rich sequence of structural transformations,…

Thermonuclear burning on the surface of accreting neutron stars is observed to stabilize at accretion rates almost an order of magnitude lower than theoretical models predict. One way to resolve this discrepancy is by including a base…

Solar and Stellar Astrophysics · Physics 2015-06-22 Michael Zamfir , Andrew Cumming , Caroline Niquette

The energy landscape of helium-nitrogen mixtures is explored by ab initio evolutionary searches, which predicted several stable helium-nitrogen compounds in the pressure range from 25 to 100 GPa. In particular, the monoclinic structure of…

The equation of state for hydrogen and helium is fundamental for studying stars and giant planets. It has been shown that because of interactions at atomic and molecular levels, the behaviour of a mixture of hydrogen and helium cannot be…

Earth and Planetary Astrophysics · Physics 2023-03-29 Saburo Howard , Tristan Guillot

The present work reports on the new soft ferromagnetic Heusler phases Fe2NiGe, Fe2CuGa, and Fe2CuAl, which in previous theoretical studies have been predicted to exist in a tetragonal regular Heusler structure. Together with the known…

Materials Science · Physics 2014-04-18 T. Gasi , V. Ksenofontov , J. Kiss , S. Chadov , A. K. Nayak , M. Nicklas , J. Winterlik , M. Schwall , P. Klaer , P. Adler , C. Felser

A previously unknown thermodynamically stable high-pressure phase of BeF$_{2}$ has been predicted using the evolutionary algorithm USPEX. This phase occurs in the pressure range 18-27 GPa. Its structure has $C2/c$ space group symmetry and…

Since the discovery of superconductivity in a high-entropy alloy (HEA) Ti-Zr-Nb-Hf-Ta in 2014, the community of superconductor science has explored new HEA superconductors to find the merit of the HEA states on superconducting properties.…

Superconductivity · Physics 2021-03-16 Y. Mizuguchi , A. Yamashita

Rare-earth hydrides can exhibit high-temperature superconductivity under high pressure. Here, we apply a crystal structure prediction method to the current record-holding $T_c$ material, LaH$_{10}$, and a candidate for even higher $T_c$,…

The elastic and magnetic properties, thermodynamical stability, deviation from stoichiometry and order/disorder transformations of phases that are relevant to Be alloys were investigated using density functional theory simulations coupled…

Materials Science · Physics 2015-04-01 Patrick A. Burr , Simon C. Middleburgh , Robin W. Grimes

The chemical composition of an exoplanet is a key ingredient in constraining its formation history. Iron is the most abundant transition metal, but has never been directly detected in an exoplanet due to its highly refractory nature.…

We have used density-functional-theory methods and the ab initio random structure searching (AIRSS) approach to predict stable structures and stoichiometries of mixtures of iron and oxygen at high pressures. Searching was performed for 12…

Materials Science · Physics 2015-08-24 Gihan L. Weerasinghe , R. J. Needs , Chris J. Pickard

Supersolid is a mysterious and puzzling state of matter whose possible existence has stirred a vigorous debate among physicists for over 60 years. Its elusive nature stems from the coexistence of two seemingly contradicting properties,…

Materials Science · Physics 2022-02-09 Chang Woo Myung , Barak Hirshberg , Michele Parrinello
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