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Wright JA, Green E, Kuhns P, Reyes A, Brooks J, Schlueter J, Kato R, Yamamoto H, Kobayashi M, Brown SE. Zeeman-driven phase transition within the superconducting state of κ-(BEDT-TTF)2Cu(NCS)2. PHYSICAL REVIEW LETTERS 2011; 107:087002. [PMID: 21929196 DOI: 10.1103/physrevlett.107.087002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Indexed: 05/31/2023]
Abstract
(13)C nuclear magnetic resonance measurements were performed on κ-(BEDT-TTF)(2)Cu(NCS)(2), with the external field placed parallel to the quasi-2D conducting layers. The absorption spectrum is used to determine the electronic spin polarization M(s) as a function of external field H at a temperature T=0.35 K. A discontinuity in the derivative dM(s)/dH at an applied field of H(s)=213±3 kOe is taken as evidence for a Zeeman-driven transition within the superconducting state and stabilization of inhomogeneous superconductivity.
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Affiliation(s)
- J A Wright
- Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547, USA
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Nakai Y, Ishida K, Kamihara Y, Hirano M, Hosono H. Spin dynamics in iron-based layered superconductor (La0.87Ca0.13)FePO revealed by 31P and 139La NMR studies. PHYSICAL REVIEW LETTERS 2008; 101:077006. [PMID: 18764571 DOI: 10.1103/physrevlett.101.077006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Indexed: 05/26/2023]
Abstract
We report 31P and 139La NMR studies of (La0.87Ca0.13)FePO, which is a family member of the recently discovered superconductor LaFeAs(O1-xFx). In the normal state, Knight shift and nuclear spin-lattice relaxation rate divided by T (1/T1T) show that a Fermi-liquid state with moderate ferromagnetic fluctuations emerges below 30 K. From 1/T1T of 31P and 139La, a quasi-two- dimensional electronic structure is suggested, in which the FeP layer is more conductive than the LaO layer. In the superconducting (SC) state, although a clear Meissner signal was observed, 1/T1T increases below Tc, in contrast to a decrease of 1/T1T due to the opening of a SC gap, suggesting that novel low-energy spin dynamics develop in the SC state.
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Affiliation(s)
- Yusuke Nakai
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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Grafe HJ, Paar D, Lang G, Curro NJ, Behr G, Werner J, Hamann-Borrero J, Hess C, Leps N, Klingeler R, Büchner B. 75As NMR studies of superconducting LaFeAsO0.9F0.1. PHYSICAL REVIEW LETTERS 2008; 101:047003. [PMID: 18764358 DOI: 10.1103/physrevlett.101.047003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Indexed: 05/26/2023]
Abstract
We have performed 75As nuclear magnetic resonance measurements on aligned powders of the new LaFeAsO0.9F0.1 superconductor. In the normal state, we find a strong temperature dependence of the spin shift and Korringa behavior of the spin lattice relaxation rate. In the superconducting state, we find evidence for line nodes in the superconducting gap and spin-singlet pairing. Our measurements reveal a strong anisotropy of the spin lattice relaxation rate, which suggests that superconducting vortices contribute to the relaxation rate when the field is parallel to the c axis but not for the perpendicular direction.
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Affiliation(s)
- H-J Grafe
- IFW Dresden, Institute for Solid State Research, P.O. Box 270116, D-01171 Dresden, Germany
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Kurosaki Y, Shimizu Y, Miyagawa K, Kanoda K, Saito G. Mott transition from a spin liquid to a Fermi liquid in the spin-frustrated organic conductor kappa-(ET)2Cu2(CN)3. PHYSICAL REVIEW LETTERS 2005; 95:177001. [PMID: 16383857 DOI: 10.1103/physrevlett.95.177001] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Revised: 04/06/2005] [Indexed: 05/05/2023]
Abstract
The pressure-temperature phase diagram of the organic Mott insulator kappa-(ET)2Cu2(CN)3, a model system of the spin liquid on triangular lattice, has been investigated by 1H NMR and resistivity measurements. The spin-liquid phase is persistent before the Mott transition to the metal or superconducting phase under pressure. At the Mott transition, the spin fluctuations are rapidly suppressed and the Fermi-liquid features are observed in the temperature dependence of the spin-lattice relaxation rate and resistivity. The characteristic curvature of the Mott boundary in the phase diagram highlights a crucial effect of the spin frustration on the Mott transition.
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Affiliation(s)
- Y Kurosaki
- Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan
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Miyagawa K, Kanoda K, Kawamoto A. NMR Studies on Two-Dimensional Molecular Conductors and Superconductors: Mott Transition in κ-(BEDT-TTF)2X. Chem Rev 2004; 104:5635-54. [PMID: 15535663 DOI: 10.1021/cr0306541] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kazuya Miyagawa
- Department of Applied Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan
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Singer PM, Imai T, He T, Hayward MA, Cava RJ. (13)C NMR investigation of the superconductor MgCNi(3) up to 800 K. PHYSICAL REVIEW LETTERS 2001; 87:257601. [PMID: 11736604 DOI: 10.1103/physrevlett.87.257601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2001] [Indexed: 05/23/2023]
Abstract
We report (13)C NMR characterization of the new superconductor MgCNi(3) [T. He et al., Nature (London) 411, 54 (2001)]. We found that both the uniform spin susceptibility and the spin fluctuations show a strong enhancement with decreasing temperature, and saturate below approximately 50 K and approximately 20 K, respectively. The nuclear spin-lattice relaxation rate 1/(13)T(1) exhibits typical behavior for isotropic s-wave superconductivity with a coherence peak below T(c) = 7.0 K that grows with decreasing magnetic field.
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Affiliation(s)
- P M Singer
- Department of Physics and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Slichter CP, Kini AM, Wang HH, Geiser U, Williams JM. 13C NMR line-shape studies of the organic superconductor kappa -(ET)2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:16101-16107. [PMID: 9985684 DOI: 10.1103/physrevb.54.16101] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Corti M, Suh BJ, Tabak F, Rigamonti A, Borsa F, Xu M, Dabrowski B. Flux-line dynamics in YBa2Cu4O8 from 89Y NMR. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:9469-9474. [PMID: 9984686 DOI: 10.1103/physrevb.54.9469] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Zimmer G, Mehring M, Rachdi F, Fischer JE. Vortex dynamics in Rb3C60 observed by 87Rb and 13C NMR. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R3768-R3771. [PMID: 9986368 DOI: 10.1103/physrevb.54.r3768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kanoda K, Miyagawa K, Kawamoto A, Nakazawa Y. NMR relaxation rate in the superconducting state of the organic conductor kappa -(BEDT-TTF)2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:76-79. [PMID: 9984228 DOI: 10.1103/physrevb.54.76] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Mayaffre H, Wzietek P, Jérome D, Brazovskii S. Two-Dimensional Vortex Melting in BEDT Organic Superconductors and NMR Relaxation Induced by Vortex Structure Defects. PHYSICAL REVIEW LETTERS 1996; 76:4951-4954. [PMID: 10061421 DOI: 10.1103/physrevlett.76.4951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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12
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Suh BJ, Borsa F, Sok J, Torgeson DR, Corti M, Rigamonti A, Xiong Q. Thermal depinning of flux lines in HgBa2CuO4+ delta from 199Hg spin-lattice relaxation. PHYSICAL REVIEW LETTERS 1996; 76:1928-1931. [PMID: 10060556 DOI: 10.1103/physrevlett.76.1928] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Mayaffre H, Wzietek P, Jérome D, Lenoir C, Batail P. Superconducting state of kappa -(ET)2CUBr studied by 13C NMR: Evidence for vortex-core-induced nuclear relaxation and unconventional pairing. PHYSICAL REVIEW LETTERS 1995; 75:4122-4125. [PMID: 10059820 DOI: 10.1103/physrevlett.75.4122] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Slichter CP, Kini AM, Wang HH, Geiser U, Williams JM. 13C NMR studies of the normal and superconducting states of the organic superconductor kappa -(ET)2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:10364-10368. [PMID: 9980088 DOI: 10.1103/physrevb.52.10364] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Miyagawa K, Kawamoto A, Nakazawa Y, Kanoda K. Antiferromagnetic ordering and spin structure in the organic conductor, kappa -(BEDT-TTF)2Cu. PHYSICAL REVIEW LETTERS 1995; 75:1174-1177. [PMID: 10060224 DOI: 10.1103/physrevlett.75.1174] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Truong KD, Achkir D, Jandl S, Poirier M. Raman-active intramolecular CH2 and C=C vibrations and microwave surface impedance studies of the organic superconductor kappa -. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:16168-16173. [PMID: 9978600 DOI: 10.1103/physrevb.51.16168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kawamoto A, Miyagawa K, Nakazawa Y, Kanoda K. 13C NMR Study of Layered Organic Superconductors Based on BEDT-TTF Molecules. PHYSICAL REVIEW LETTERS 1995; 74:3455-3458. [PMID: 10058205 DOI: 10.1103/physrevlett.74.3455] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Lahaise UG, Chen Q, Brock CP, Wang HH, Carlson KD, Schlueter JA, Williams JM. Anomalous vortex dynamics in kappa -. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 51:3301-3304. [PMID: 9979134 DOI: 10.1103/physrevb.51.3301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Dressel M, Klein O, Grüner G, Carlson KD, Wang HH, Williams JM. Electrodynamics of the organic superconductorsinebreak kappa -(BEDT-TTF)2Cu(NCS)2 and kappa -(BEDT-TTF)2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:13603-13615. [PMID: 9975555 DOI: 10.1103/physrevb.50.13603] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Martindale JA, Barrett SE, Durand DJ, O'Hara KE, Slichter CP, Lee WC, Ginsberg DM. Nuclear-spin-lattice relaxation-rate measurements in YBa2Cu3O7. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:13645-13652. [PMID: 9975561 DOI: 10.1103/physrevb.50.13645] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Vulcanescu V, Collin G, Kojima H, Tanaka I, Fruchter L. Locked-unlocked transition of the flux-line-lattice configuration for a (La1-xSrx)2CuO4 (x=0.075) single crystal with a small demagnetizing factor. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:4139-4143. [PMID: 9976698 DOI: 10.1103/physrevb.50.4139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Xing L, Chang YC. Nuclear spin-lattice relaxation induced by thermally fluctuating flux lines. PHYSICAL REVIEW LETTERS 1994; 73:488-491. [PMID: 10057459 DOI: 10.1103/physrevlett.73.488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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23
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Lang M, Steglich F, Toyota N, Sasaki T. Fluctuation effects and mixed-state properties of the layered organic superconductors kappa -(BEDT-TTF)2Cu(NCS)2 and kappa -(BEDT-TTF)2Cu. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:15227-15234. [PMID: 10010630 DOI: 10.1103/physrevb.49.15227] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Harshman DR, Fiory AT, Haddon RC, Kaplan ML, Pfiz T, Koster E, Shinkoda I, Williams DL. Magnetic penetration depth and fluxon-line dynamics in the organic superconductor kappa -. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:12990-12997. [PMID: 10010211 DOI: 10.1103/physrevb.49.12990] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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