101
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Zhou HD, Xu C, Hallas AM, Silverstein HJ, Wiebe CR, Umegaki I, Yan JQ, Murphy TP, Park JH, Qiu Y, Copley JRD, Gardner JS, Takano Y. Successive phase transitions and extended spin-excitation continuum in the S=1/2 triangular-lattice antiferromagnet Ba3CoSb2O9. PHYSICAL REVIEW LETTERS 2012; 109:267206. [PMID: 23368612 DOI: 10.1103/physrevlett.109.267206] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Indexed: 06/01/2023]
Abstract
Using magnetic, thermal, and neutron measurements on single-crystal samples, we show that Ba3CoSb2O9 is a spin-1/2 triangular-lattice antiferromagnet with the c axis as the magnetic easy axis and two magnetic phase transitions bracketing an intermediate up-up-down phase in magnetic field applied along the c axis. A pronounced extensive neutron-scattering continuum above spin-wave excitations, observed below T(N), implies that the system is in close proximity to one of two spin-liquid states that have been predicted for a 2D triangular lattice.
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Affiliation(s)
- H D Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
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102
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Nakamura T, Sasamori K, Kodama T, Kikuchi K, Fujita W. Preparation, crystal structure, and magnetic properties of a new dithiolene ligand, 1,3,2-dithiazole-4-thione-5-thiolate, and its metal complex. Chem Asian J 2012; 8:348-50. [PMID: 23239526 DOI: 10.1002/asia.201200912] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 10/28/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Tadamitsu Nakamura
- Department of Chemistry, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji 192-0397, Japan
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103
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Kusamoto T, Yamamoto HM, Tajima N, Oshima Y, Yamashita S, Kato R. Bilayer Mott System Based on Ni(dmit)2 (dmit = 1,3-dithiole-2-thione-4,5-dithiolate) Anion Radicals: Two Isostructural Salts Exhibit Contrasting Magnetic Behavior. Inorg Chem 2012; 51:11645-54. [DOI: 10.1021/ic301552z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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104
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Fujita W, Kikuchi K, Mori W. Crystal Growth, Structure, and Magnetic Properties of a Two-dimensional Triangular Lattice Magnet, Cu2(OH)3HCO2. Chem Asian J 2012; 7:2830-5. [DOI: 10.1002/asia.201200732] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Indexed: 11/11/2022]
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105
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106
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Potter AC, Barkeshli M, McGreevy J, Senthil T. Quantum spin liquids and the metal-insulator transition in doped semiconductors. PHYSICAL REVIEW LETTERS 2012; 109:077205. [PMID: 23006401 DOI: 10.1103/physrevlett.109.077205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Indexed: 06/01/2023]
Abstract
We describe a new possible route to the metal-insulator transition in doped semiconductors such as Si:P or Si:B. We explore the possibility that the loss of metallic transport occurs through Mott localization of electrons into a quantum spin liquid state with diffusive charge neutral "spinon" excitations. Such a quantum spin liquid state can appear as an intermediate phase between the metal and the Anderson-Mott insulator. An immediate testable consequence is the presence of metallic thermal conductivity at low temperature in the electrical insulator near the metal-insulator transition. Further, we show that though the transition is second order, the zero temperature residual electrical conductivity will jump as the transition is approached from the metallic side. However, the electrical conductivity will have a nonmonotonic temperature dependence that may complicate the extrapolation to zero temperature. Signatures in other experiments and some comparisons with existing data are made.
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Affiliation(s)
- Andrew C Potter
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, USA
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107
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Cation Dependence of Crystal Structure and Band Parameters in a Series of Molecular Conductors, β'-(Cation)[Pd(dmit)2]2 (dmit = 1,3-dithiole-2-thione-4,5-dithiolate). CRYSTALS 2012. [DOI: 10.3390/cryst2030861] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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108
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Nakatsuji S, Kuga K, Kimura K, Satake R, Katayama N, Nishibori E, Sawa H, Ishii R, Hagiwara M, Bridges F, Ito TU, Higemoto W, Karaki Y, Halim M, Nugroho AA, Rodriguez-Rivera JA, Green MA, Broholm C. Spin-Orbital Short-Range Order on a Honeycomb-Based Lattice. Science 2012; 336:559-63. [DOI: 10.1126/science.1212154] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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109
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110
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Lieffrig J, Jeannin O, Auban-Senzier P, Fourmigué M. Chiral Conducting Salts of Nickel Dithiolene Complexes. Inorg Chem 2012; 51:7144-52. [DOI: 10.1021/ic300146s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Julien Lieffrig
- Sciences Chimiques de Rennes, Université Rennes 1 and CNRS UMR 6226, Campus
de Beaulieu, 35042 Rennes, France
| | - Olivier Jeannin
- Sciences Chimiques de Rennes, Université Rennes 1 and CNRS UMR 6226, Campus
de Beaulieu, 35042 Rennes, France
| | - Pascale Auban-Senzier
- Laboratoire de Physique des
Solides, Université Paris Sud, CNRS,
UMR 8502, 91405 Orsay, France
| | - Marc Fourmigué
- Sciences Chimiques de Rennes, Université Rennes 1 and CNRS UMR 6226, Campus
de Beaulieu, 35042 Rennes, France
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111
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Xu C, Wang F, Qi Y, Balents L, Fisher MPA. Spin liquid phases for spin-1 systems on the triangular lattice. PHYSICAL REVIEW LETTERS 2012; 108:087204. [PMID: 22463565 DOI: 10.1103/physrevlett.108.087204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Indexed: 05/31/2023]
Abstract
Motivated by recent experiments on material Ba3NiSb2O9, we propose two novel spin liquid phases (A and B) for spin-1 systems on a triangular lattice. At the mean field level, both spin liquid phases have gapless fermionic spinon excitations with quadratic band touching; thus, in both phases the spin susceptibility and γ=C(v)/T saturate to a constant at zero temperature, which are consistent with the experimental results on Ba3NiSb2O9. On the lattice scale, these spin liquid phases have Sp(4)~SO(5) gauge fluctuation, while in the long wavelength limit this Sp(4) gauge symmetry is broken down to U(1)×Z(2) in the type A spin liquid phase, and broken down to Z(4) in the type B phase. We also demonstrate that the A phase is the parent state of the ferroquadrupole state, nematic state, and the noncollinear spin density wave state.
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Affiliation(s)
- Cenke Xu
- Department of Physics, University of California, Santa Barbara, California 93106, USA
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112
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Isakov SV, Melko RG, Hastings MB. Universal Signatures of Fractionalized Quantum Critical Points. Science 2012; 335:193-5. [DOI: 10.1126/science.1212207] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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113
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Cheng JG, Li G, Balicas L, Zhou JS, Goodenough JB, Xu C, Zhou HD. High-pressure sequence of Ba3NiSb2O9 structural phases: new S = 1 quantum spin liquids based on Ni2+. PHYSICAL REVIEW LETTERS 2011; 107:197204. [PMID: 22181641 DOI: 10.1103/physrevlett.107.197204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Indexed: 05/31/2023]
Abstract
Two new gapless quantum spin-liquid candidates with S = 1 (Ni(2+)) moments: the 6H-B phase of Ba(3)NiSb(2)O(9) with a Ni(2+)-triangular lattice and the 3C phase with a Ni(2/3)Sb(1/3)-three-dimensional edge-shared tetrahedral lattice were obtained under high pressure. Both compounds show no magnetic order down to 0.35 K despite Curie-Weiss temperatures θ(CW) of -75.5 (6H-B) and -182.5 K (3C), respectively. Below ~25 K, the magnetic susceptibility of the 6H-B phase saturates to a constant value χ(0) = 0.013 emu/mol, which is followed below 7 K by a linear-temperature-dependent magnetic specific heat (C(M)) displaying a giant coefficient γ = 168 mJ/mol K(2). Both observations suggest the development of a Fermi-liquid-like ground state. For the 3C phase, the C(M) perpendicular T(2) behavior indicates a unique S = 1, 3D quantum spin-liquid ground state.
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Affiliation(s)
- J G Cheng
- Texas Materials Institute, University of Texas at Austin, Texas 78712, USA
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114
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Yamashita M, Shibauchi T, Matsuda Y. Thermal-Transport Studies on Two-Dimensional Quantum Spin Liquids. Chemphyschem 2011; 13:74-8. [PMID: 22012837 DOI: 10.1002/cphc.201100556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Indexed: 11/11/2022]
Affiliation(s)
- Minoru Yamashita
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake, Sakyo, Kyoto, Japan.
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115
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Gapless spin liquid of an organic triangular compound evidenced by thermodynamic measurements. Nat Commun 2011; 2:275. [PMID: 21505431 PMCID: PMC3104558 DOI: 10.1038/ncomms1274] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 03/14/2011] [Indexed: 12/05/2022] Open
Abstract
In frustrated magnetic systems, long-range ordering is forbidden and degeneracy of energy states persists, even at extremely low temperatures. Under certain conditions, these systems form an exotic quantum spin-liquid ground state, in which strongly correlated spins fluctuate in the spin lattices. Here we investigate the thermodynamic properties of an anion radical spin liquid of EtMe3Sb[Pd(dmit)2]2, where dmit represents 1,3-dithiole-2-thione-4,5-dithiolate. This compound is an organic dimer-based Mott insulator with a two-dimensional triangular lattice structure. We present distinct evidence for the formation of a gapless spin liquid by examining the T-linear heat capacity coefficient, γ , in the low-temperature heat capacity. Using comparative analyses with κ-(BEDT-TTF)2Cu2(CN)3, a generalized picture of the new spin liquid in dimer-based organic systems is discussed. We also report anomalous enhancement of γ, produced by a kind of criticality inherent to the Pd(dmit)2 phase diagram. Frustrated magnetic systems can form an exotic quantum spin-liquid ground state, in which strongly correlated spins fluctuate in the spin lattices. Here, the low-temperature electronic state of a charge-transfer compound is found to form a gapless spin liquid.
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116
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Zhang Y, Grover T, Vishwanath A. Entanglement entropy of critical spin liquids. PHYSICAL REVIEW LETTERS 2011; 107:067202. [PMID: 21902364 DOI: 10.1103/physrevlett.107.067202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Indexed: 05/31/2023]
Abstract
Quantum spin liquids are phases of matter whose internal structure is not captured by a local order parameter. Particularly intriguing are critical spin liquids, where strongly interacting excitations control low energy properties. Here we calculate their bipartite entanglement entropy that characterizes their quantum structure. In particular we calculate the Renyi entropy S(2) on model wave functions obtained by Gutzwiller projection of a Fermi sea. Although the wave functions are not sign positive, S(2) can be calculated on relatively large systems (>324 spins) using the variational Monte Carlo technique. On the triangular lattice we find that entanglement entropy of the projected Fermi sea state violates the boundary law, with S(2) enhanced by a logarithmic factor. This is an unusual result for a bosonic wave function reflecting the presence of emergent fermions. These techniques can be extended to study a wide class of other phases.
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Affiliation(s)
- Yi Zhang
- Department of Physics, University of California, Berkeley, 94720, USA
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117
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Block MS, Sheng DN, Motrunich OI, Fisher MPA. Spin Bose-metal and valence bond solid phases in a spin-1/2 model with ring exchanges on a four-leg triangular ladder. PHYSICAL REVIEW LETTERS 2011; 106:157202. [PMID: 21568607 DOI: 10.1103/physrevlett.106.157202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 01/28/2011] [Indexed: 05/30/2023]
Abstract
We study a spin-1/2 system with Heisenberg plus ring exchanges on a four-leg triangular ladder using the density matrix renormalization group and Gutzwiller variational wave functions. Near an isotropic lattice regime, for moderate to large ring exchanges we find a spin Bose-metal phase with a spinon Fermi sea consisting of three partially filled bands. Going away from the triangular towards the square lattice regime, we find a staggered dimer phase with dimers in the transverse direction, while for small ring exchanges the system is in a featureless rung phase. We also discuss parent states and a possible phase diagram in two dimensions.
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Affiliation(s)
- Matthew S Block
- Department of Physics, University of California, Santa Barbara, California 93106, USA
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118
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Zhou HD, Choi ES, Li G, Balicas L, Wiebe CR, Qiu Y, Copley JRD, Gardner JS. Spin liquid state in the S = 1/2 triangular lattice Ba3CuSb2O9. PHYSICAL REVIEW LETTERS 2011; 106:147204. [PMID: 21561219 DOI: 10.1103/physrevlett.106.147204] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 05/30/2023]
Abstract
The synthesis and characterization of Ba3CuSb2O9, which has a layered array of Cu2+ spins in a triangular lattice, are reported. The magnetic susceptibility and neutron scattering experiments of this material show no magnetic ordering down to 0.2 K with a θ(CW) = -55 K. The magnetic specific heat reveals a T-linear dependence with a γ = 43.4 mJ K(-2) mol(-1) below 1.4 K. These observations suggest that Ba3CuSb2O9 is a new quantum spin liquid candidate with a S = 1/2 triangular lattice.
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Affiliation(s)
- H D Zhou
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306-4005, USA.
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119
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Magnetic and non-magnetic phases of a quantum spin liquid. Nature 2011; 471:612-6. [DOI: 10.1038/nature09910] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 02/07/2011] [Indexed: 11/08/2022]
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120
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Rau JG, Kee HY. Emergence of superconductivity, valence bond order, and Mott insulators in Pd[(dmit)2] based organic salts. PHYSICAL REVIEW LETTERS 2011; 106:056405. [PMID: 21405417 DOI: 10.1103/physrevlett.106.056405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Indexed: 05/30/2023]
Abstract
The EtMe(3)P and EtMe(3)Sb triangular organic salts are distinguished from other Pd[(dmit)(2)] based salts, as they display valence bond and no long-range order, respectively. Under pressure, a superconducting phase is revealed in EtMe(3)P near the boundary of valence bond order. We use slave-rotor theory with an enlarged unit cell to study competition between uniform and broken translational symmetry states, offering a theoretical framework capturing the superconducting, valence bond order, spin liquid, and metallic phases on an isotropic triangular lattice. Our finite temperature phase diagram manifests a remarkable resemblance to the phase diagram of the EtMe(3)P salt, where the reentrant transition of insulator-metal-insulator type can be explained by an entropy difference between the metal and U(1) spin liquid. We predict different temperature dependence of the specific heat between the spin liquid and metal.
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Affiliation(s)
- Jeffrey G Rau
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
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121
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Zhou Y, Lee PA. Spinon phonon interaction and ultrasonic attenuation in quantum spin liquids. PHYSICAL REVIEW LETTERS 2011; 106:056402. [PMID: 21405414 DOI: 10.1103/physrevlett.106.056402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Indexed: 05/30/2023]
Abstract
Several experimental candidates for quantum spin liquids have been discovered in the past few years which appear to support gapless fermionic S=1/2 excitations called spinons. The spinons may form a Fermi sea coupled to a U(1) gauge field, and may undergo a pairing instability. We show that despite being charge neutral, the spinons couple to phonons in exactly the same way that electrons do in the long wavelength limit. Therefore, we can use sound attenuation to measure the spinon mass and lifetime. Furthermore, transverse ultrasonic attenuation is a direct probe of the onset of pairing because the Meissner effect of the gauge field causes a "rapid fall" of the attenuation at T(c) in addition to the reduction due to the opening of the energy gap. This phenomenon, well known in clean superconductors, may reveal the existence of the U(1) gauge field.
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Affiliation(s)
- Yi Zhou
- Department of Physics and Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, 310027, People's Republic of China
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122
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Nomura M. Organometallic dithiolene complexes of the group 8–10 metals: Reactivities, structures and electrochemical behavior. Dalton Trans 2011; 40:2112-40. [DOI: 10.1039/c0dt01025a] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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