1
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Verma AK, Mishra AK, Modak P. Novel ground state structures of N-doped LuH 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:425702. [PMID: 38955341 DOI: 10.1088/1361-648x/ad5e52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 07/01/2024] [Indexed: 07/04/2024]
Abstract
Ab-initiocrystal structure searches have played a pivotal role in recent discoveries of high-Tc hydride superconductors under high pressure. Using evolutionary crystal searches, we predict novel ground state structures of N-doped LuH3at ambient conditions. We find an insulating ground state structure for LuN0.125H2.875(∼1.0 wt.% N), contrary to earlier studies where assumed structures were all metallic. This insulating behavior of ground state was found to persist up to ∼45 GPa. However our crystal structure searches revealed a metallic state for an H-deficient variant of LuN0.125H2.875. We study bonding characteristics of important structures by calculating electronic density of states, electronic-localization functions and Bader charges. Our Bader charge analysis shows that insulators have both H+and H-ions whereas metals have only H-ions. We find that H+ions are bonded to N atomsviaa very short covalent bond. Thus we identify a clear relationship between formation of N-H bonds and insulating behavior of materials. Besides this, we perform crystal structure searches for three more compositions with higher N-content (>1.0 wt.%). Analysis of electronic properties shows that the ground states of these compositions are insulator.
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Affiliation(s)
- Ashok K Verma
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Ajay K Mishra
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - P Modak
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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2
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Hou P, Ma Y, Pang M, Cai Y, Shen Y, Xie H, Tian F. Anharmonic and quantum effects in Pm3̄ AlM(M = Hf, Zr)H6 under high pressure: A first-principles study. J Chem Phys 2024; 161:024504. [PMID: 38984960 DOI: 10.1063/5.0219790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Accepted: 06/25/2024] [Indexed: 07/11/2024] Open
Abstract
First-principles calculations were employed to investigate the impact of quantum ionic fluctuations and lattice anharmonicity on the crystal structure and superconductivity of Pm3̄ AlM(M = Hf, Zr)H6 at pressures of 0.3-21.2 GPa (AlHfH6) and 4.7-39.5 GPa (AlZrH6) within the stochastic self-consistent harmonic approximation. A correction is predicted for the crystal lattice parameters, phonon spectra, and superconducting critical temperatures, previously estimated without considering ionic fluctuations on the crystal structure and assuming the harmonic approximation for lattice dynamics. The findings suggest that quantum ionic fluctuations have a significant impact on the crystal lattice parameters, phonon spectra, and superconducting critical temperatures. Based on our anharmonic phonon spectra, the structures will be dynamically stable at 0.3 GPa for AlHfH6 and 6.2 GPa for AlZrH6, ∼6 and 7 GPa lower than pressures given by the harmonic approximation, respectively. Due to the anharmonic correction of their frequencies, the electron-phonon coupling constants (λ) are suppressed by 28% at 11 GPa for AlHfH6 and 22% at 30 GPa for AlZrH6, respectively. The decrease in λ causes Tc to be overestimated by ∼12 K at 11 GPa for AlHfH6 and 30 GPa for AlZrH6. Even if the anharmonic and quantum effects are not as strong as those of Pm3̄n-AlH3, our results also indicate that metal hydrides with hydrogen atoms in interstitial sites are subject to anharmonic effects. Our results will inevitably stimulate future high-pressure experiments on synthesis, structural, and conductivity measurements.
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Affiliation(s)
- Pugeng Hou
- College of Science, Northeast Electric Power University, Changchun Road 169, 132012 Jilin, People's Republic of China
| | - Yao Ma
- Department of Applied Physics, School of Sciences, Xi'an University of Technology, Xi'an 710048, People's Republic of China
| | - Mi Pang
- Department of Applied Physics, School of Sciences, Xi'an University of Technology, Xi'an 710048, People's Republic of China
| | - Yongmao Cai
- College of Science, Northeast Electric Power University, Changchun Road 169, 132012 Jilin, People's Republic of China
| | - Yuhua Shen
- College of Science, Northeast Electric Power University, Changchun Road 169, 132012 Jilin, People's Republic of China
| | - Hui Xie
- College of Physics and Electronic Engineering, Hebei Minzu Normal University, Chengde 067000, People's Republic of China
| | - Fubo Tian
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China
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3
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Peng D, Zeng Q, Lan F, Xing Z, Zeng Z, Ke X, Ding Y, Mao HK. Origin of the near-room temperature resistance transition in lutetium with H 2/N 2 gas mixture under high pressure. Natl Sci Rev 2024; 11:nwad337. [PMID: 38883294 PMCID: PMC11173200 DOI: 10.1093/nsr/nwad337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/07/2023] [Accepted: 12/15/2023] [Indexed: 06/18/2024] Open
Abstract
The recent report of room-temperature superconductivity at near-ambient pressure in nitrogen-doped lutetium hydride (Lu-H-N) by Dasenbrock-Gammon et al. [Nature 615, 244-250 (2023)] has attracted tremendous attention due to its anticipated great impact on technology. However, the results could not be independently reproduced by other groups worldwide in follow-up studies, which elicited intense controversy. Here, we develop a reliable experimental protocol to minimize the extensively concerned extrinsic influences on the sample by starting the reaction from pure lutetium loaded with an H2/N2 gas mixture in a diamond anvil cell under different pressures and temperatures and simultaneously monitoring the entire chemical reaction process using in situ four-probe resistance measurements. Therefore, we could repeatedly reproduce the near-room temperature upsurge of electrical resistance at a relatively early stage of the chemical reaction. However, the mechanism is suggested to be a metal-to-semiconductor/insulator transition associated with the structural modulation in the non-stoichiometric Lu-H-N, rather than superconductivity.
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Affiliation(s)
- Di Peng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Sciences, Hefei 230031, China
- Science Island Branch, Graduate School of University of Science and Technology of China, Hefei 230026, China
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Qiaoshi Zeng
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments (MFree), Shanghai Advanced Research in Physical Sciences (SHARPS), Shanghai 201203, China
| | - Fujun Lan
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Zhenfang Xing
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- State Key Laboratory of Superhard Materials, Institute of Physics, Jilin University, Changchun 130012, China
| | - Zhidan Zeng
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Xiaoxing Ke
- College of Materials Science & Engineering, Beijing University of Technology, Beijing 100124, China
| | - Yang Ding
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
| | - Ho-Kwang Mao
- Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
- Shanghai Key Laboratory of Material Frontiers Research in Extreme Environments (MFree), Shanghai Advanced Research in Physical Sciences (SHARPS), Shanghai 201203, China
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4
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Chen S, Wu Z, Zhang Z, Wu S, Ho KM, Antropov V, Sun Y. High-Throughput Screening for Boride Superconductors. Inorg Chem 2024; 63:8654-8663. [PMID: 38682814 DOI: 10.1021/acs.inorgchem.4c00159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
A high-throughput screening using density functional calculations is performed to search for stable boride superconductors from the existing materials database. The workflow employs the fast frozen-phonon method as the descriptor to evaluate the superconducting properties quickly. Twenty-three stable candidates were identified during the screening. The superconductivity was obtained earlier experimentally or computationally for almost all found binary compounds. Previous studies on ternary borides are very limited. Our extensive search among ternary systems confirmed superconductivity in known systems and found several new compounds. Among these discovered superconducting ternary borides, TaMo2B2 shows the highest superconducting temperature of ∼12 K. Most predicted compounds were synthesized previously; therefore, our predictions can be examined experimentally. Our work also demonstrates that the boride systems can have diverse structural motifs that lead to superconductivity.
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Affiliation(s)
- Shiya Chen
- Department of Physics, Xiamen University, Xiamen 361005, China
| | - Zepeng Wu
- Department of Physics, Xiamen University, Xiamen 361005, China
| | - Zhen Zhang
- Department of Physics, Iowa State University, Ames, Iowa 50011, United States
| | - Shunqing Wu
- Department of Physics, Xiamen University, Xiamen 361005, China
| | - Kai-Ming Ho
- Department of Physics, Iowa State University, Ames, Iowa 50011, United States
| | | | - Yang Sun
- Department of Physics, Xiamen University, Xiamen 361005, China
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5
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Tang BL. Publishing important work that lacks validity or reproducibility - pushing frontiers or corrupting science? Account Res 2024:1-21. [PMID: 38698587 DOI: 10.1080/08989621.2024.2345714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 04/04/2024] [Indexed: 05/05/2024]
Abstract
Scientific research requires objectivity, impartiality and stringency. However, scholarly literature is littered with preliminary and explorative findings that lack reproducibility or validity. Some low-quality papers with perceived high impact have become publicly notable. The collective effort of fellow researchers who follow these false leads down blind alleys and impasses is a waste of time and resources, and this is particularly damaging for early career researchers. Furthermore, the lay public might also be affected by socioeconomic repercussions associated with the findings. It is arguable that the nature of scientific research is such that its frontiers are moved and shaped by cycles of published claims inducing in turn rounds of validation by others. Using recent example cases of room-temperature superconducting materials research, I argue instead that publication of perceptibly important or spectacular claims that lack reproducibility or validity is epistemically and socially irresponsible. This is even more so if authors refuse to share research materials and raw data for verification by others. Such acts do not advance, but would instead corrupt science, and should be prohibited by consensual governing rules on material and data sharing within the research community, with malpractices appropriately sanctioned.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Republic of Singapore
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6
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Dolui K, Conway LJ, Heil C, Strobel TA, Prasankumar RP, Pickard CJ. Feasible Route to High-Temperature Ambient-Pressure Hydride Superconductivity. PHYSICAL REVIEW LETTERS 2024; 132:166001. [PMID: 38701475 DOI: 10.1103/physrevlett.132.166001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/01/2024] [Indexed: 05/05/2024]
Abstract
A key challenge in materials discovery is to find high-temperature superconductors. Hydrogen and hydride materials have long been considered promising materials displaying conventional phonon-mediated superconductivity. However, the high pressures required to stabilize these materials have restricted their application. Here, we present results from high-throughput computation, considering a wide range of high-symmetry ternary hydrides from across the periodic table at ambient pressure. This large composition space is then reduced by considering thermodynamic, dynamic, and magnetic stability before direct estimations of the superconducting critical temperature. This approach has revealed a metastable ambient-pressure hydride superconductor, Mg_{2}IrH_{6}, with a predicted critical temperature of 160 K, comparable to the highest temperature superconducting cuprates. We propose a synthesis route via a structurally related insulator, Mg_{2}IrH_{7}, which is thermodynamically stable above 15 GPa, and discuss the potential challenges in doing so.
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Affiliation(s)
- Kapildeb Dolui
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB30FS, United Kingdom
| | - Lewis J Conway
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB30FS, United Kingdom
- Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
| | - Christoph Heil
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Timothy A Strobel
- Earth and Planets Laboratory, Carnegie Institution for Science, 5241 Broad Branch Road, Northwest, Washington, DC 20015, USA
| | | | - Chris J Pickard
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB30FS, United Kingdom
- Advanced Institute for Materials Research, Tohoku University, Sendai, 980-8577, Japan
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7
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Almeida NMS, Welch BK, North SC, Wilson AK. Unraveling the electronic structure of LuH, LuN, and LuNH: building blocks of new materials. Phys Chem Chem Phys 2024; 26:10427-10438. [PMID: 38502323 DOI: 10.1039/d4cp00533c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Advances in superconductor technology have been pursued for decades, moving towards room temperature models, such as a postulated nitrogen-doped lutetium hydride network. While experimental observations have been contradictory, insight into the building blocks of potential new superconductor materials can be gained theoretically, unravelling the fascinating electronic structure of these compounds at a molecular level. Here, the fundamental building blocks of lutetium materials (LuH, LuN, and LuNH) have been examined. The structures, spectroscopic constants for the ground and excited states, and the potential energy curves have been obtained for these species using complete active self-consistent field (CASSCF) and multireference configuration interaction with Davidson's correction (MRCI+Q) methods. For LuNH, the energetic properties of its isomers are determined. The bond dissociation energies of the three building blocks are calculated with the state-of-the-art f-block ab initio correlation consistent composite approach (f-ccCA) and the high accuracy extrapolated ab initio thermochemistry (HEAT) scheme. As well, an analysis of different formation pathways of LuNH has been provided.
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Affiliation(s)
- Nuno M S Almeida
- Michigan State University, Department of Chemistry, East Lansing, MI 48864, USA.
| | - Bradley K Welch
- Michigan State University, Department of Chemistry, East Lansing, MI 48864, USA.
| | - Sasha C North
- Michigan State University, Department of Chemistry, East Lansing, MI 48864, USA.
| | - Angela K Wilson
- Michigan State University, Department of Chemistry, East Lansing, MI 48864, USA.
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8
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Lucrezi R, Ferreira PP, Aichhorn M, Heil C. Temperature and quantum anharmonic lattice effects on stability and superconductivity in lutetium trihydride. Nat Commun 2024; 15:441. [PMID: 38199988 PMCID: PMC10781996 DOI: 10.1038/s41467-023-44326-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024] Open
Abstract
In this work, we resolve conflicting experimental and theoretical findings related to the dynamical stability and superconducting properties of [Formula: see text]-LuH3, which was recently suggested as the parent phase harboring room-temperature superconductivity at near-ambient pressures. Including temperature and quantum anharmonic lattice effects in our calculations, we demonstrate that the theoretically predicted structural instability of the [Formula: see text] phase near ambient pressures is suppressed for temperatures above 200 K. We provide a p-T phase diagram for stability up to pressures of 6 GPa, where the required temperature for stability is reduced to T > 80 K. We also determine the superconducting critical temperature Tc of [Formula: see text]-LuH3 within the Migdal-Eliashberg formalism, using temperature- and quantum-anharmonically-corrected phonon dispersions, finding that the expected Tc for electron-phonon mediated superconductivity is in the range of 50-60 K, i.e., well below the temperatures required to stabilize the lattice. When considering moderate doping based on rigidly shifting the Fermi level, Tc decreases for both hole and electron doping. Our results thus provide evidence that any observed room-temperature superconductivity in pure or doped [Formula: see text]-LuH3, if confirmed, cannot be explained by a conventional electron-phonon mediated pairing mechanism.
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Affiliation(s)
- Roman Lucrezi
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Pedro P Ferreira
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
- Universidade de São Paulo, Escola de Engenharia de Lorena, DEMAR, 12612-550, Lorena, Brazil
| | - Markus Aichhorn
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria
| | - Christoph Heil
- Institute of Theoretical and Computational Physics, Graz University of Technology, NAWI Graz, 8010 Graz, Austria.
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9
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Kim SW, Conway LJ, Pickard CJ, Pascut GL, Monserrat B. Microscopic theory of colour in lutetium hydride. Nat Commun 2023; 14:7360. [PMID: 37963870 PMCID: PMC10646004 DOI: 10.1038/s41467-023-42983-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/25/2023] [Indexed: 11/16/2023] Open
Abstract
Nitrogen-doped lutetium hydride has recently been proposed as a near-ambient-conditions superconductor. Interestingly, the sample transforms from blue to pink to red as a function of pressure, but only the pink phase is claimed to be superconducting. Subsequent experimental studies have failed to reproduce the superconductivity, but have observed pressure-driven colour changes including blue, pink, red, violet, and orange. However, discrepancies exist among these experiments regarding the sequence and pressure at which these colour changes occur. Given the claimed relationship between colour and superconductivity, understanding colour changes in nitrogen-doped lutetium hydride may hold the key to clarifying the possible superconductivity in this compound. Here, we present a full microscopic theory of colour in lutetium hydride, revealing that hydrogen-deficient LuH2 is the only phase which exhibits colour changes under pressure consistent with experimental reports, with a sequence blue-violet-pink-red-orange. The concentration of hydrogen vacancies controls the precise sequence and pressure of colour changes, rationalising seemingly contradictory experiments. Nitrogen doping also modifies the colour of LuH2 but it plays a secondary role compared to hydrogen vacancies. Therefore, we propose hydrogen-deficient LuH2 as the key phase for exploring the superconductivity claim in the lutetium-hydrogen system. Finally, we find no phonon-mediated superconductivity near room temperature in the pink phase.
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Affiliation(s)
- Sun-Woo Kim
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK.
| | - Lewis J Conway
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK
- Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577, Japan
| | - Chris J Pickard
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK
- Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577, Japan
| | - G Lucian Pascut
- MANSiD Research Center and Faculty of Forestry, Stefan Cel Mare University (USV), Suceava, 720229, Romania
| | - Bartomeu Monserrat
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge, CB3 0FS, UK.
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
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10
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Xing X, Wang C, Yu L, Xu J, Zhang C, Zhang M, Huang S, Zhang X, Liu Y, Yang B, Chen X, Zhang Y, Guo J, Shi Z, Ma Y, Chen C, Liu X. Observation of non-superconducting phase changes in nitrogen doped lutetium hydrides. Nat Commun 2023; 14:5991. [PMID: 37752133 PMCID: PMC10522599 DOI: 10.1038/s41467-023-41777-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
The recent report of near-ambient superconductivity and associated color changes in pressurized nitrogen doped lutetium hydride has triggered worldwide interest and raised major questions about the nature and underlying physics of these latest claims. Here we report synthesis and characterization of high-purity nitrogen doped lutetium hydride LuH2±xNy. We find that pressure conditions have notable effects on Lu-N and Lu-NH chemical bonding and the color changes likely stem from pressure-induced electron redistribution of nitrogen/vacancies and interaction with the LuH2 framework. No superconducting transition is found in all the phases at temperatures 1.8-300 K and pressures 0-38 GPa. Instead, we identify a notable temperature-induced resistance anomaly of electronic origin in LuH2±xNy, which is most pronounced in the pink phase and may have been erroneously interpreted as a sign of superconducting transition. This work establishes key benchmarks for nitrogen doped lutetium hydrides, allowing an in-depth understanding of its novel pressure-induced phase changes.
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Affiliation(s)
- Xiangzhuo Xing
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Chao Wang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Linchao Yu
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Jie Xu
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Chutong Zhang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Mengge Zhang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Song Huang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Xiaoran Zhang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
| | - Yunxian Liu
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Bingchao Yang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Xin Chen
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Yongsheng Zhang
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China
| | - Jiangang Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhixiang Shi
- School of Physics, Southeast University, Nanjing, 211189, China
| | - Yanming Ma
- Innovation Center for Computational Methods & Software, College of Physics, Jilin University, Changchun, 130012, China
- State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012, China
- International Center of Future Science, Jilin University, Changchun, 130012, China
| | - Changfeng Chen
- Department of Physics and Astronomy, University of Nevada, Las Vegas, NV, 89154, USA
| | - Xiaobing Liu
- Laboratory of High Pressure Physics and Material Science (HPPMS), School of Physics and Physical Engineering, Qufu Normal University, Qufu, 273165, China.
- Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu, 273165, China.
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11
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Ming X, Zhang YJ, Zhu X, Li Q, He C, Liu Y, Huang T, Liu G, Zheng B, Yang H, Sun J, Xi X, Wen HH. Absence of near-ambient superconductivity in LuH 2±xN y. Nature 2023; 620:72-77. [PMID: 37168015 PMCID: PMC10396964 DOI: 10.1038/s41586-023-06162-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
A recent study demonstrated near-ambient superconductivity in nitrogen-doped lutetium hydride1. This stimulated a worldwide interest in exploring room-temperature superconductivity at low pressures. Here, by using a high-pressure and high-temperature synthesis technique, we have obtained nitrogen-doped lutetium hydride (LuH2±xNy), which has a dark-blue colour and a structure with the space group [Formula: see text] as evidenced by X-ray diffraction. This structure is the same as that reported in ref. 1, with a slight difference in lattice constant. Raman spectroscopy of our samples also showed patterns similar to those observed in ref. 1. Energy-dispersive X-ray spectroscopy confirmed the presence of nitrogen in the samples. We observed a metallic behaviour from 350 K to 2 K at ambient pressure. On applying pressures from 2.1 GPa to 41 GPa, we observed a gradual colour change from dark blue to violet to pink-red. By measuring the resistance at pressures ranging from 0.4 GPa to 40.1 GPa, we observed a progressively improved metallic behaviour; however, superconductivity was not observed above 2 K. Temperature dependence of magnetization at high pressure shows a very weak positive signal between 100 K and 320 K, and the magnetization increases with an increase in magnetic field at 100 K. All of these are not expected for superconductivity above 100 K. Thus, we conclude the absence of near-ambient superconductivity in this nitrogen-doped lutetium hydride at pressures below 40.1 GPa.
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Affiliation(s)
- Xue Ming
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Ying-Jie Zhang
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Xiyu Zhu
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
| | - Qing Li
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
| | - Chengping He
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Yuecong Liu
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Tianheng Huang
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Gan Liu
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Bo Zheng
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Huan Yang
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Jian Sun
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Xiaoxiang Xi
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Hai-Hu Wen
- National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
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