1
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Loa I, Landgren F. On: X-ray diffraction from the electron gas in monatomic metallic hydrogen. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:185401. [PMID: 38215491 DOI: 10.1088/1361-648x/ad1e08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 01/12/2024] [Indexed: 01/14/2024]
Abstract
Solid hydrogen is expected to become a monatomic metal under sufficiently high compression. With hydrogen having only a single valence electron and no ion core, the nature of x-ray diffraction patterns from the electron gas of monatomic metallic hydrogen is uncertain, and it is unclear whether they may yield enough information for a crystal structure determination. With emphasis on the Cs-IV-type (I41/amd) structure predicted for hydrogen at ∼500 GPa, the electron density distributions, zero-point and thermal atomic motion, and x-ray diffraction intensities are determined from first-principles calculations for several candidate phases of metallic hydrogen. It is shown that the electron distribution is much more structured than might be expected from the commonly employed free-electron-gas picture, and in fact more modulated than what is obtained from the superposition of free-atom charge densities. We demonstrate that an identification of the crystal structure of monatomic metallic hydrogen from x-ray diffraction is fundamentally possible and discuss the possibility of single-crystal diffraction from metallic hydrogen. An atomic scattering factor for the hydrogen atom in monatomic metallic hydrogen is constructed to aid the quantitative analysis of diffraction intensities from future x-ray diffraction experiments.
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Affiliation(s)
- Ingo Loa
- SUPA, School of Physics and Astronomy and Centre for Science at Extreme Conditions, The University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
| | - Filip Landgren
- SUPA, School of Physics and Astronomy and Centre for Science at Extreme Conditions, The University of Edinburgh, Edinburgh EH9 3FD, United Kingdom
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2
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Ying J, Liu S, Lu Q, Wen X, Gui Z, Zhang Y, Wang X, Sun J, Chen X. Record High 36 K Transition Temperature to the Superconducting State of Elemental Scandium at a Pressure of 260 GPa. PHYSICAL REVIEW LETTERS 2023; 130:256002. [PMID: 37418707 DOI: 10.1103/physrevlett.130.256002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/04/2023] [Accepted: 06/05/2023] [Indexed: 07/09/2023]
Abstract
Elemental materials provide clean and fundamental platforms for studying superconductivity. However, the highest superconducting critical temperature (T_{c}) yet observed in elements has not exceeded 30 K. Discovering elemental superconductors with a higher T_{c} is one of the most fundamental and challenging tasks in condensed matter physics. In this study, by applying high pressure up to approximately 260 GPa, we demonstrate that the superconducting transition temperature of elemental scandium (Sc) can be increased to 36 K from the transport measurement, which is a record-high T_{c} for superconducting elements. The pressure dependence of T_{c} implies the occurrence of multiple phase transitions in Sc, which is in agreement with previous x-ray diffraction results. Optimization of T_{c} is achieved in the Sc-V phase, which can be attributed to the strong coupling between d electrons and moderate-frequency phonons, as suggested by our first-principles calculations. This study provides insights for exploring new high-T_{c} elemental metals.
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Affiliation(s)
- Jianjun Ying
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shiqiu Liu
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qing Lu
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xikai Wen
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhigang Gui
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yuqing Zhang
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaomeng Wang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian Sun
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xianhui Chen
- Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, Anhui 230026, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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3
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Du M, Zhao W, Cui T, Duan D. Compressed superhydrides: the road to room temperature superconductivity. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:173001. [PMID: 35078164 DOI: 10.1088/1361-648x/ac4eaf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
Room-temperature superconductivity has been a long-held dream and an area of intensive research. The discovery of H3S and LaH10under high pressure, with superconducting critical temperatures (Tc) above 200 K, sparked a race to find room temperature superconductors in compressed superhydrides. In recent groundbreaking work, room-temperature superconductivity of 288 K was achieved in carbonaceous sulfur hydride at 267 GPa. Here, we describe the important attempts of hydrides in the process of achieving room temperature superconductivity in decades, summarize the main characteristics of high-temperature hydrogen-based superconductors, such as hydrogen structural motifs, bonding features, electronic structure as well as electron-phonon coupling etc. This work aims to provide an up-to-date summary of several type hydrogen-based superconductors based on the hydrogen structural motifs, including covalent superhydrides, clathrate superhydrides, layered superhydrides, and hydrides containing isolated H atom, H2and H3molecular units.
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Affiliation(s)
- Mingyang Du
- College of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Wendi Zhao
- Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, Ningbo, 315211, People's Republic of China
| | - Tian Cui
- College of Physics, Jilin University, Changchun 130012, People's Republic of China
- Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, Ningbo, 315211, People's Republic of China
| | - Defang Duan
- College of Physics, Jilin University, Changchun 130012, People's Republic of China
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4
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Li B, Ding Y, Kim DY, Wang L, Weng TC, Yang W, Yu Z, Ji C, Wang J, Shu J, Chen J, Yang K, Xiao Y, Chow P, Shen G, Mao WL, Mao HK. Probing the Electronic Band Gap of Solid Hydrogen by Inelastic X-Ray Scattering up to 90 GPa. PHYSICAL REVIEW LETTERS 2021; 126:036402. [PMID: 33543962 DOI: 10.1103/physrevlett.126.036402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/07/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
Metallization of hydrogen as a key problem in modern physics is the pressure-induced evolution of the hydrogen electronic band from a wide-gap insulator to a closed gap metal. However, due to its remarkably high energy, the electronic band gap of insulating hydrogen has never before been directly observed under pressure. Using high-brilliance, high-energy synchrotron radiation, we developed an inelastic x-ray probe to yield the hydrogen electronic band information in situ under high pressures in a diamond-anvil cell. The dynamic structure factor of hydrogen was measured over a large energy range of 45 eV. The electronic band gap was found to decrease linearly from 10.9 to 6.57 eV, with an 8.6 times densification (ρ/ρ_{0}∼8.6) from zero pressure up to 90 GPa.
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Affiliation(s)
- Bing Li
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Yang Ding
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Duck Young Kim
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Lin Wang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- Center for High Pressure Science (CHiPS), State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China
| | - Tsu-Chien Weng
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Wenge Yang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Zhenhai Yu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Cheng Ji
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- HPCAT, X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Junyue Wang
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Jinfu Shu
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Jiuhua Chen
- Center for the Study of Matter at Extreme Conditions, Department of Mechanical and Materials Engineering, Florida International University, Miami, Florida 33199, USA
| | - Ke Yang
- Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Yuming Xiao
- HPCAT, X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Paul Chow
- HPCAT, X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Guoyin Shen
- HPCAT, X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Wendy L Mao
- Department of Geological Sciences, Stanford University, Stanford, California 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
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5
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Silvera IF, Dias R. Phases of the hydrogen isotopes under pressure: metallic hydrogen. ADVANCES IN PHYSICS: X 2021. [DOI: 10.1080/23746149.2021.1961607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
| | - Ranga Dias
- Department of Physics and Astronomy and Mechanical Engineering, University of Rochester, Rochester, USA
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6
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Characterization of molecular-atomic transformation in fluid hydrogen under pressure via long-wavelength asymptote of charge density fluctuations. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Gorelov V, Holzmann M, Ceperley DM, Pierleoni C. Energy Gap Closure of Crystalline Molecular Hydrogen with Pressure. PHYSICAL REVIEW LETTERS 2020; 124:116401. [PMID: 32242714 DOI: 10.1103/physrevlett.124.116401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/13/2020] [Indexed: 06/11/2023]
Abstract
We study the gap closure with pressure of crystalline molecular hydrogen. The gaps are obtained from grand-canonical quantum Monte Carlo methods properly extended to quantum and thermal crystals, simulated by coupled electron ion Monte Carlo methods. Nuclear zero point effects cause a large reduction in the gap (∼2 eV). Depending on the structure, the fundamental indirect gap closes between 380 and 530 GPa for ideal crystals and 330-380 GPa for quantum crystals. Beyond this pressure the system enters into a bad metal phase where the density of states at the Fermi level increases with pressure up to ∼450-500 GPa when the direct gap closes. Our work partially supports the interpretation of recent experiments in high pressure hydrogen.
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Affiliation(s)
- Vitaly Gorelov
- Université Paris-Saclay, UVSQ, CNRS, CEA, Maison de la Simulation, 91191, Gif-sur-Yvette, France
| | - Markus Holzmann
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
- Institut Laue-Langevin, BP 156, F-38042 Grenoble Cedex 9, France
| | - David M Ceperley
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Carlo Pierleoni
- Université Paris-Saclay, UVSQ, CNRS, CEA, Maison de la Simulation, 91191, Gif-sur-Yvette, France
- Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio 10, I-67010 L'Aquila, Italy
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8
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Cui TT, Li JC, Gao W, Hermann J, Tkatchenko A, Jiang Q. Nonlocal Electronic Correlations in the Cohesive Properties of High-Pressure Hydrogen Solids. J Phys Chem Lett 2020; 11:1521-1527. [PMID: 32031376 DOI: 10.1021/acs.jpclett.9b03716] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High-pressure hydrogen exhibits remarkable phenomena including the insulator-to-metal (IM) transition; however, a complete resolution of its phase diagram is still an elusive goal despite many efforts and much controversy. Theoretical modeling is typically based on density functional theory (DFT) with a mean-field description of electronic correlations, which is known to be rather limited in describing IM transitions. Herein, we show that nonlocal electron correlations play a central role in the relative stability of solid hydrogen phases, and that DFT-correcting for these correlations by the many-body dispersion (MBD) model reaches the accuracy of quantum Monte Carlo (QMC) simulations and predicts the same C2/c-24 → Cmca-12 → Cs(IV) IM transition. In contrast with the conventional assumption that many-body electronic correlations become localized in metallic systems because of exponential screening with interelectronic distance, we find that the anisotropy of the electronic response of hydrogen solids under pressure leads to longer-ranged many-body effects in metallic phases relative to insulating ones. This refines our understanding of phase diagram of hydrogen solids as well as anisotropic many-body correlations.
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Affiliation(s)
- Ting-Ting Cui
- Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Department of Materials Science and Engineering , Jilin University , Changchun 130022 , China
| | - Jian-Chen Li
- Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Department of Materials Science and Engineering , Jilin University , Changchun 130022 , China
| | - Wang Gao
- Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Department of Materials Science and Engineering , Jilin University , Changchun 130022 , China
| | - Jan Hermann
- Physics and Materials Science Research Unit , University of Luxembourg , L-1511 Luxembourg City , Luxembourg
| | - Alexandre Tkatchenko
- Physics and Materials Science Research Unit , University of Luxembourg , L-1511 Luxembourg City , Luxembourg
| | - Qing Jiang
- Key Laboratory of Automobile Materials (Jilin University), Ministry of Education, Department of Materials Science and Engineering , Jilin University , Changchun 130022 , China
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9
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Lesik M, Plisson T, Toraille L, Renaud J, Occelli F, Schmidt M, Salord O, Delobbe A, Debuisschert T, Rondin L, Loubeyre P, Roch JF. Magnetic measurements on micrometer-sized samples under high pressure using designed NV centers. Science 2019; 366:1359-1362. [DOI: 10.1126/science.aaw4329] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 11/06/2019] [Indexed: 01/24/2023]
Abstract
Pressure can be used to tune the interplay among structural, electronic, and magnetic interactions in materials. High pressures are usually applied in the diamond anvil cell, making it difficult to study the magnetic properties of a micrometer-sized sample. We report a method for spatially resolved optical magnetometry based on imaging a layer of nitrogen-vacancy (NV) centers created at the surface of a diamond anvil. We illustrate the method using two sets of measurements realized at room temperature and low temperature, respectively: the pressure evolution of the magnetization of an iron bead up to 30 gigapascals showing the iron ferromagnetic collapse and the detection of the superconducting transition of magnesium dibromide at 7 gigapascals.
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Affiliation(s)
- Margarita Lesik
- Laboratoire Aimé Cotton, CNRS, Univ. Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405 Orsay Cedex, France
| | | | - Loïc Toraille
- Laboratoire Aimé Cotton, CNRS, Univ. Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405 Orsay Cedex, France
| | | | | | - Martin Schmidt
- Laboratoire Aimé Cotton, CNRS, Univ. Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405 Orsay Cedex, France
| | | | | | | | - Loïc Rondin
- Laboratoire Aimé Cotton, CNRS, Univ. Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405 Orsay Cedex, France
| | | | - Jean-François Roch
- Laboratoire Aimé Cotton, CNRS, Univ. Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, 91405 Orsay Cedex, France
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10
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Xiao X, Duan D, Xie H, Shao Z, Li D, Tian F, Song H, Yu H, Bao K, Cui T. Structure and superconductivity of protactinium hydrides under high pressure. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:315403. [PMID: 31026850 DOI: 10.1088/1361-648x/ab1d03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We systematically study the stability, crystal structure, electronic property, and superconductivity of protactinium hydride (PaH n ) (n = 1-9) at a pressure range of 1 atm to 300 GPa by using the first principle of density functional theory. PaH n compounds are very rich, featuring six stoichiometries, such as PaH, PaH3, PaH4, PaH5, PaH8 and PaH9. PaH8 possesses the highly symmetrical crystal structure Fm-3m with cubic H8 units, which is predicted to be thermodynamically stable above 32 GPa. This phase maintains a dynamically stable decompression at 10 GPa. Electron-phonon coupling (EPC) calculations show that Fm-3m-PaH8 exhibits high superconducting critical transition temperature (T c) value of 79 K at 10 GPa due to a strong EPC and large logarithmic average frequency. The T c values of Fm-3m-PaH8 decrease with increasing pressure. Interestingly, superconducting PaH8 appears at low pressure, prompting experimental research.
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Affiliation(s)
- Xuehui Xiao
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China
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11
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Affiliation(s)
- Wei Fang
- School of Physics and Collaborative Innovation Centre of Quantum Matter, Peking University, Beijing, People's Republic of China
- Thomas Young Centre, London Centre for Nanotechnology, and Department of Physics and Astronomy, University College London, London, UK
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Ji Chen
- Department of Electronic Structure Theory, Max Plank Institute for Solid State Research, Stuttgart, Germany
| | - Yexin Feng
- School of Physics and Electronics, Hunan University, Changsha, People's Republic of China
| | - Xin-Zheng Li
- School of Physics and Collaborative Innovation Centre of Quantum Matter, Peking University, Beijing, People's Republic of China
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Peking University, Beijing, People's Republic of China
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology, and Department of Physics and Astronomy, University College London, London, UK
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12
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Band gap closure, incommensurability and molecular dissociation of dense chlorine. Nat Commun 2019; 10:1134. [PMID: 30850606 PMCID: PMC6408506 DOI: 10.1038/s41467-019-09108-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 02/21/2019] [Indexed: 11/08/2022] Open
Abstract
Diatomic elemental solids are highly compressible due to the weak interactions between molecules. However, as the density increases the intra- and intermolecular distances become comparable, leading to a range of phenomena, such as structural transformation, molecular dissociation, amorphization, and metallisation. Here we report, following the crystallization of chlorine at 1.15(30) GPa into an ordered orthorhombic structure (oC8), the existence of a mixed-molecular structure (mC8, 130(10)-241(10) GPa) and the concomitant observation of a continuous band gap closure, indicative of a transformation into a metallic molecular form around 200(10) GPa. The onset of dissociation of chlorine is identified by the observation of the incommensurate structure (i-oF4) above 200(10) GPa, before finally adopting a monatomic form (oI2) above 256(10) GPa.
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13
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Zurek E, Bi T. High-temperature superconductivity in alkaline and rare earth polyhydrides at high pressure: A theoretical perspective. J Chem Phys 2019; 150:050901. [DOI: 10.1063/1.5079225] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Eva Zurek
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
| | - Tiange Bi
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
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14
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O'Bannon EF, Jenei Z, Cynn H, Lipp MJ, Jeffries JR. Contributed Review: Culet diameter and the achievable pressure of a diamond anvil cell: Implications for the upper pressure limit of a diamond anvil cell. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:111501. [PMID: 30501343 DOI: 10.1063/1.5049720] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/14/2018] [Indexed: 06/09/2023]
Abstract
Recently, static pressures of more than 1.0 TPa have been reported, which raises the question: what is the maximum static pressure that can be achieved using diamond anvil cell techniques? Here we compile culet diameters, bevel diameters, bevel angles, and reported pressures from the literature. We fit these data and find an expression that describes the maximum pressure as a function of the culet diameter. An extrapolation of our fit reveals that a culet diameter of 1 μm should achieve a pressure of ∼1.8 TPa. Additionally, for pressure generation of ∼400 GPa with a single beveled diamond anvil, the most commonly reported parameters are a culet diameter of ∼20 μm, a bevel angle of 8.5°, and a bevel diameter to culet diameter ratio between 14 and 18. Our analysis shows that routinely generating pressures more than ∼300 GPa likely requires diamond anvil geometries that are fundamentally different from a beveled or double beveled anvil (e.g., toroidal or double stage anvils) and culet diameters that are ≤20 μm.
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Affiliation(s)
- Earl F O'Bannon
- Physical and Life Sciences, Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Zsolt Jenei
- Physical and Life Sciences, Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Hyunchae Cynn
- Physical and Life Sciences, Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Magnus J Lipp
- Physical and Life Sciences, Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - Jason R Jeffries
- Physical and Life Sciences, Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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15
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Silvera IF, Dias R. Metallic hydrogen. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:254003. [PMID: 29749966 DOI: 10.1088/1361-648x/aac401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hydrogen is the simplest and most abundant element in the Universe. There are two pathways for creating metallic hydrogen under high pressures. Over 80 years ago Wigner and Huntington predicted that if solid molecular hydrogen was sufficiently compressed in the T = 0 K limit, molecules would dissociate to form atomic metallic hydrogen (MH). We have observed this transition at a pressure of 4.95 megabars. MH in this form has probably never existed on Earth or in the Universe; it may be a room temperature superconductor and is predicted to be metastable. If metastable it will have an important technological impact. Liquid metallic hydrogen can also be produced at intermediate pressures and high temperatures and is believed to make up ~90% of the planet Jupiter. We have observed this liquid-liquid transition, also known as the plasma phase transition, at pressures of ~1-2 megabar and temperatures ~1000-2000 K. However, in this paper we shall focus on the Wigner-Huntington transition. We shall discuss the methods used to observe metallic hydrogen at extreme conditions of static pressure in the laboratory, extending our understanding of the phase diagram of the simplest atom in the periodic table.
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Affiliation(s)
- Isaac F Silvera
- Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138, United States of America
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16
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Monserrat B, Drummond ND, Dalladay-Simpson P, Howie RT, López Ríos P, Gregoryanz E, Pickard CJ, Needs RJ. Structure and Metallicity of Phase V of Hydrogen. PHYSICAL REVIEW LETTERS 2018; 120:255701. [PMID: 29979086 DOI: 10.1103/physrevlett.120.255701] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/17/2018] [Indexed: 06/08/2023]
Abstract
A new phase V of hydrogen was recently claimed in experiments above 325 GPa and 300 K. Because of the extremely small sample size at such record pressures the measurements were limited to Raman spectroscopy. The experimental data on increase of pressure show decreasing Raman activity and darkening of the sample, which suggests band gap closure and impending molecular dissociation, but no definite conclusions could be reached. Furthermore, the available data are insufficient to determine the structure of phase V, which remains unknown. Introducing saddle-point ab initio random structure searching, we find several new structural candidates of hydrogen which could describe the observed properties of phase V. We investigate hydrogen metallization in the proposed candidate structures, and demonstrate that smaller band gaps are associated with longer bond lengths. We conclude that phase V is a stepping stone towards metallization.
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Affiliation(s)
- Bartomeu Monserrat
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019, USA
- TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Neil D Drummond
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Philip Dalladay-Simpson
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Ross T Howie
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
| | - Pablo López Ríos
- TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
- Max-Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Eugene Gregoryanz
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, People's Republic of China
- Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Chris J Pickard
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
- Advanced Institute for Materials Research, Tohoku University 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
| | - Richard J Needs
- TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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17
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Geballe ZM, Liu H, Mishra AK, Ahart M, Somayazulu M, Meng Y, Baldini M, Hemley RJ. Synthesis and Stability of Lanthanum Superhydrides. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709970] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Zachary M. Geballe
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
| | - Hanyu Liu
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
| | - Ajay K. Mishra
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
- Permanent address: HP&SRPD Bhabha Atomic Research Center Mumbai-85 India
| | - Muhtar Ahart
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
| | - Maddury Somayazulu
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
| | - Yue Meng
- HPCAT Geophysical Laboratory Carnegie Institution of Washington Argonne IL 60439 USA
| | - Maria Baldini
- Geophysical Laboratory Carnegie Institution of Washington Washington DC 20015 USA
| | - Russell J. Hemley
- Institute of Materials Science and Department of Civil and Environmental Engineering The George Washington University Washington DC 20052 USA
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18
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Synthesis and Stability of Lanthanum Superhydrides. Angew Chem Int Ed Engl 2017; 57:688-692. [DOI: 10.1002/anie.201709970] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Indexed: 11/07/2022]
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19
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Silvera IF, Dias R. Response to Comment on “Observation of the Wigner-Huntington transition to metallic hydrogen”. Science 2017; 357:357/6353/eaan2671. [DOI: 10.1126/science.aan2671] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/19/2017] [Indexed: 11/02/2022]
Affiliation(s)
- Isaac F. Silvera
- Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Ranga Dias
- Lyman Laboratory of Physics, Harvard University, Cambridge, MA 02138, USA
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