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Hu K, Li Q, Song D, Jia Y, Liang Z, Wang S, Du H, Wen HH, Ge B. Atomic scale disorder and reconstruction in bulk infinite-layer nickelates lacking superconductivity. Nat Commun 2024; 15:5104. [PMID: 38877022 PMCID: PMC11178912 DOI: 10.1038/s41467-024-49533-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 06/07/2024] [Indexed: 06/16/2024] Open
Abstract
The recent discovery of superconductivity in infinite-layer nickelate films has sparked significant interest and expanded the realm of superconductors, in which the infinite-layer structure and proper chemical doping are both of the essence. Nonetheless, the reasons for the absence of superconductivity in bulk infinite-layer nickelates remain puzzling. Herein, we investigate atomic defects and electronic structures in bulk infinite-layer Nd0.8Sr0.2NiO2 using scanning transmission electron microscopy. Our observations reveal the presence of three-dimensional (3D) block-like structural domains resulting from intersecting defect structures, disrupting the continuity within crystal grains, which could be a crucial factor in giving rise to the insulating character and inhibiting the emergence of superconductivity. Moreover, the infinite-layer structure, without complete topotactic reduction, retains interstitial oxygen atoms on the Nd atomic plane in bulk nickelates, possibly further aggravating the local distortions of NiO2 planes and hindering the superconductivity. These findings shed light on the existence of structural and atomic defects in bulk nickelates and provide valuable insights into the influence of proper topotactic reduction and structural orders on superconductivity.
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Affiliation(s)
- Kejun Hu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Qing Li
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Dongsheng Song
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China.
| | - Yingze Jia
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Zhiyao Liang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Shuai Wang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Haifeng Du
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Hai-Hu Wen
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China.
| | - Binghui Ge
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China.
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2
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Gao R, Jin L, Huyan S, Ni D, Wang H, Xu X, Bud'ko SL, Canfield P, Xie W, Cava RJ. Is La 3Ni 2O 6.5 a Bulk Superconducting Nickelate? ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38381798 DOI: 10.1021/acsami.3c17376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Superconducting states onsetting at moderately high temperatures have been observed in epitaxially stabilized RENiO2-based thin films. However, recently, it has also been reported that superconductivity at high temperatures is observed in bulk La3Ni2O7-δ at high pressure, opening further possibilities for study. Here we report the reduction profile of La3Ni2O7 in a stream of 5% H2/Ar gas and the isolation of the metastable intermediate phase La3Ni2O6.45, which is based on Ni2+. Although this reduced phase does not superconduct at ambient or high pressures, it offers insights into the Ni-327 system and encourages future study of nickelates as a function of oxygen content.
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Affiliation(s)
- Ran Gao
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Lun Jin
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Shuyuan Huyan
- Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Danrui Ni
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Haozhe Wang
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Xianghan Xu
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Sergey L Bud'ko
- Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Paul Canfield
- Ames National Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Weiwei Xie
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Robert J Cava
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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3
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Ji H, Liu Y, Li Y, Ding X, Xie Z, Ji C, Qi S, Gao X, Xu M, Gao P, Qiao L, Yang YF, Zhang GM, Wang J. Rotational symmetry breaking in superconducting nickelate Nd 0.8Sr 0.2NiO 2 films. Nat Commun 2023; 14:7155. [PMID: 37935701 PMCID: PMC10630465 DOI: 10.1038/s41467-023-42988-8] [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: 08/16/2023] [Accepted: 10/25/2023] [Indexed: 11/09/2023] Open
Abstract
The infinite-layer nickelates, isostructural to the high-Tc cuprate superconductors, have emerged as a promising platform to host unconventional superconductivity and stimulated growing interest in the condensed matter community. Despite considerable attention, the superconducting pairing symmetry of the nickelate superconductors, the fundamental characteristic of a superconducting state, is still under debate. Moreover, the strong electronic correlation in the nickelates may give rise to a rich phase diagram, where the underlying interplay between the superconductivity and other emerging quantum states with broken symmetry is awaiting exploration. Here, we study the angular dependence of the transport properties of the infinite-layer nickelate Nd0.8Sr0.2NiO2 superconducting films with Corbino-disk configuration. The azimuthal angular dependence of the magnetoresistance (R(φ)) manifests the rotational symmetry breaking from isotropy to four-fold (C4) anisotropy with increasing magnetic field, revealing a symmetry-breaking phase transition. Approaching the low-temperature and large-magnetic-field regime, an additional two-fold (C2) symmetric component in the R(φ) curves and an anomalous upturn of the temperature-dependent critical field are observed simultaneously, suggesting the emergence of an exotic electronic phase. Our work uncovers the evolution of the quantum states with different rotational symmetries in nickelate superconductors and provides deep insight into their global phase diagram.
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Affiliation(s)
- Haoran Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Yi Liu
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China, Beijing, 100872, China
| | - Yanan Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Department of Physics, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xiang Ding
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Zheyuan Xie
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Chengcheng Ji
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Shichao Qi
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Xiaoyue Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Minghui Xu
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Peng Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871, China
| | - Liang Qiao
- School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China.
| | - Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Guang-Ming Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
- Frontier Science Center for Quantum Information, Beijing, 100084, China
| | - Jian Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing, 100190, China.
- Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
- Hefei National Laboratory, Hefei, 230088, China.
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4
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Shao TN, Zhang ZT, Qiao YJ, Zhao Q, Liu HW, Chen XX, Jiang WM, Yao CL, Chen XY, Chen MH, Dou RF, Xiong CM, Zhang GM, Yang YF, Nie JC. Kondo scattering in underdoped Nd 1-xSr xNiO 2 infinite-layer superconducting thin films. Natl Sci Rev 2023; 10:nwad112. [PMID: 37818115 PMCID: PMC10561711 DOI: 10.1093/nsr/nwad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/25/2022] [Accepted: 03/13/2023] [Indexed: 10/12/2023] Open
Abstract
The recent discovery of superconductivity in infinite-layer nickelates generates tremendous research endeavors, but the ground state of their parent compounds is still under debate. Here, we report experimental evidence for the dominant role of Kondo scattering in the underdoped Nd1-xSrxNiO2 thin films. A resistivity minimum associated with logarithmic temperature dependence in both longitudinal and Hall resistivities are observed in the underdoped Nd1-xSrxNiO2 samples before the superconducting transition. At lower temperatures down to 0.04 K, the resistivities become saturated, following the prediction of the Kondo model. A linear scaling behavior [Formula: see text] between anomalous Hall conductivity [Formula: see text] and conductivity [Formula: see text]is revealed, verifying the dominant Kondo scattering at low temperature. The effect of weak (anti-)localization is found to be secondary. Our experiments can help in clarifying the basic physics in the underdoped Nd1-xSrxNiO2 infinite-layer thin films.
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Affiliation(s)
- Ting-Na Shao
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Zi-Tao Zhang
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Yu-Jie Qiao
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Qiang Zhao
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Hai-Wen Liu
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Xin-Xiang Chen
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Wei-Min Jiang
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Chun-Li Yao
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Xing-Yu Chen
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Mei-Hui Chen
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Rui-Fen Dou
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Chang-Min Xiong
- Department of Physics, Beijing Normal University, Beijing100875, China
| | - Guang-Ming Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing100084, China
- Frontier Science Center for Quantum Information, Beijing100084, China
| | - Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing100190, China
- Songshan Lake Materials Laboratory, Dongguan523808, China
| | - Jia-Cai Nie
- Department of Physics, Beijing Normal University, Beijing100875, China
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5
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Sun H, Huo M, Hu X, Li J, Liu Z, Han Y, Tang L, Mao Z, Yang P, Wang B, Cheng J, Yao DX, Zhang GM, Wang M. Signatures of superconductivity near 80 K in a nickelate under high pressure. Nature 2023; 621:493-498. [PMID: 37437603 DOI: 10.1038/s41586-023-06408-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023]
Abstract
Although high-transition-temperature (high-Tc) superconductivity in cuprates has been known for more than three decades, the underlying mechanism remains unknown1-4. Cuprates are the only unconventional superconductors that exhibit bulk superconductivity with Tc above the liquid-nitrogen boiling temperature of 77 K. Here we observe that high-pressure resistance and mutual inductive magnetic susceptibility measurements showed signatures of superconductivity in single crystals of La3Ni2O7 with maximum Tc of 80 K at pressures between 14.0 GPa and 43.5 GPa. The superconducting phase under high pressure has an orthorhombic structure of Fmmm space group with the [Formula: see text] and [Formula: see text] orbitals of Ni cations strongly mixing with oxygen 2p orbitals. Our density functional theory calculations indicate that the superconductivity emerges coincidently with the metallization of the σ-bonding bands under the Fermi level, consisting of the [Formula: see text] orbitals with the apical oxygen ions connecting the Ni-O bilayers. Thus, our discoveries provide not only important clues for the high-Tc superconductivity in this Ruddlesden-Popper double-layered perovskite nickelates but also a previously unknown family of compounds to investigate the high-Tc superconductivity mechanism.
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Affiliation(s)
- Hualei Sun
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Mengwu Huo
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Xunwu Hu
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Jingyuan Li
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Zengjia Liu
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Yifeng Han
- School of Molecular Sciences, Center for Materials of the Universe, Arizona State University, Tempe, AZ, USA
| | - Lingyun Tang
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou, China
| | - Zhongquan Mao
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou, China
| | - Pengtao Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Bosen Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Jinguang Cheng
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Dao-Xin Yao
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China
| | - Guang-Ming Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, China.
| | - Meng Wang
- Center for Neutron Science and Technology, Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, China.
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6
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Yang YF. An emerging global picture of heavy fermion physics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 35:103002. [PMID: 36542859 DOI: 10.1088/1361-648x/acadc4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
Recent progresses using state-of-the-art experimental techniques have motivated a number of new insights on heavy fermion physics. This article gives a brief summary of the author's research along this direction. We discuss five major topics including: (1) development of phase coherence and two-stage hybridization; (2) two-fluid behavior and hidden universal scaling; (3) quantum phase transitions and fractionalized heavy fermion liquid; (4) quantum critical superconductivity; (5) material-specific properties. These cover the most essential parts of heavy fermion physics and lead to an emerging global picture beyond conventional theories based on mean-field or local approximations.
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Affiliation(s)
- Yi-Feng Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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7
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Xie T, Liu C, Kajimoto R, Ikeuchi K, Li S, Luo H. Spin fluctuations in the 112-type iron-based superconductor Ca 0.82La 0.18Fe 0.96Ni 0.04As 2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:474001. [PMID: 36137515 DOI: 10.1088/1361-648x/ac9441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) Ca0.82La0.18Fe0.96Ni0.04As2(CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space groupI4/mmm) at room temperature and an in-plane stripe-type antiferromagnetic (AF) order at low temperature, the 112 system has a noncentrosymmetric structure (space groupP21) with additional zigzag arsenic chains between Ca/La layers and a magnetic ground state with similar wavevectorQAFbut different orientations of ordered moments in the parent compounds. Our INS study clearly reveals that the in-plane dispersions and the bandwidth of spin excitations in the superconducting CaLa-112 closely resemble to those in 122 systems. While the total fluctuating moments⟨m2⟩≈4.6±0.2μB2/Fe are larger than 122 system, the dynamic correlation lengths are similar (ξ ≈ 10 Å). These results suggest that superconductivity in iron arsenides may have a common magnetic origin under similar magnetic exchange couplings with a dual nature from local moments and itinerant electrons, despite their different magnetic patterns and lattice symmetries.
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Affiliation(s)
- Tao Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
| | - Chang Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Ryoichi Kajimoto
- Materials and Life Science Division, J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - Kazuhiko Ikeuchi
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, Tokai, Ibaraki 319-1106, Japan
| | - Shiliang Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Huiqian Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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8
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Pressure-induced monotonic enhancement of T c to over 30 K in superconducting Pr 0.82Sr 0.18NiO 2 thin films. Nat Commun 2022; 13:4367. [PMID: 35902566 PMCID: PMC9334608 DOI: 10.1038/s41467-022-32065-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/14/2022] [Indexed: 11/09/2022] Open
Abstract
The successful synthesis of superconducting infinite-layer nickelate thin films with the highest Tc ≈ 15 K has ignited great enthusiasm for this material class as potential analogs of the high-Tc cuprates. Pursuing a higher Tc is always an imperative task in studying a new superconducting material system. Here we report high-quality Pr0.82Sr0.18NiO2 thin films with Tconset ≈ 17 K synthesized by carefully tuning the amount of CaH2 in the topotactic chemical reduction and the effect of pressure on its superconducting properties by measuring electrical resistivity under various pressures in a cubic anvil cell apparatus. We find that the onset temperature of the superconductivity, Tconset, can be enhanced monotonically from ~17 K at ambient pressure to ~31 K at 12.1 GPa without showing signatures of saturation upon increasing pressure. This encouraging result indicates that the Tc of infinite-layer nickelates superconductors still has room to go higher and it can be further boosted by applying higher pressures or strain engineering in the heterostructure films.
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