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Tafra E, Basletić M, Ivek T, Kuveždić M, Novosel N, Tomić S, Korin-Hamzić B, Čulo M. Charge Transport in the Presence of Correlations and Disorder: Organic Conductors and Manganites. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1524. [PMID: 38612039 PMCID: PMC11013020 DOI: 10.3390/ma17071524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024]
Abstract
One of the most fascinating aspects of condensed matter is its ability to conduct electricity, which is particularly pronounced in conventional metals such as copper or silver. Such behavior stems from a strong tendency of valence electrons to delocalize in a periodic potential created by ions in the crystal lattice of a given material. In many advanced materials, however, this basic delocalization process of the valence electrons competes with various processes that tend to localize these very same valence electrons, thus driving the insulating behavior. The two such most important processes are the Mott localization, driven by strong correlation effects among the valence electrons, and the Anderson localization, driven by the interaction of the valence electrons with a strong disorder potential. These two localization processes are almost exclusively considered separately from both an experimental and a theoretical standpoint. Here, we offer an overview of our long-standing research on selected organic conductors and manganites, that clearly show the presence of both these localization processes. We discuss these results within existing theories of Mott-Anderson localization and argue that such behavior could be a common feature of many advanced materials.
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Affiliation(s)
- Emil Tafra
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička Cesta 32, HR-10000 Zagreb, Croatia; (E.T.); (M.B.)
| | - Mario Basletić
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička Cesta 32, HR-10000 Zagreb, Croatia; (E.T.); (M.B.)
| | - Tomislav Ivek
- Institut za Fiziku, Bijenička Cesta 46, HR-10000 Zagreb, Croatia; (T.I.); (N.N.); (S.T.); (B.K.-H.)
| | - Marko Kuveždić
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička Cesta 32, HR-10000 Zagreb, Croatia; (E.T.); (M.B.)
| | - Nikolina Novosel
- Institut za Fiziku, Bijenička Cesta 46, HR-10000 Zagreb, Croatia; (T.I.); (N.N.); (S.T.); (B.K.-H.)
| | - Silvia Tomić
- Institut za Fiziku, Bijenička Cesta 46, HR-10000 Zagreb, Croatia; (T.I.); (N.N.); (S.T.); (B.K.-H.)
| | - Bojana Korin-Hamzić
- Institut za Fiziku, Bijenička Cesta 46, HR-10000 Zagreb, Croatia; (T.I.); (N.N.); (S.T.); (B.K.-H.)
| | - Matija Čulo
- Institut za Fiziku, Bijenička Cesta 46, HR-10000 Zagreb, Croatia; (T.I.); (N.N.); (S.T.); (B.K.-H.)
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Barszcz B, Starodub TN, Mizera A, Świetlik R, Rytel K, Iaroshenko VO, Starodub VA. Structure, optical and electro-physical properties of tetramerized anion-radical salt (N-Xy-Qn)(TCNQ) 2. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 270:120822. [PMID: 35016064 DOI: 10.1016/j.saa.2021.120822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 12/20/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
The (N-Xy-Qn)(TCNQ)2 anion-radical salt characterized by tetramerized stacks of the TCNQ acceptor molecules has been synthesized and characterized using vibrational spectroscopy and electrical resistivity measurements. The bond lengths analysis based on the crystal structure data, indicates that the TCNQ molecules are non-uniformly charged with -0.83 e localized on the inner B molecules and -0.33 e on the outer A molecules within ABBA tetramers. Both infrared and Raman spectra of (N-Xy-Qn)(TCNQ)2 are dominated by vibrational modes of TCNQ and display splitting related to the tetramerized structure. Many of these features are affected by the strong electron-molecular vibration (EMV) coupling. Other charge-sensitive modes allowed estimation of charge localized on TCNQ, with the results that confirm the charges estimated on basis of the crystal data. Electrical measurements revealed the low-conducting behavior with room temperature conductivity value of 2.6 mS cm-1 and temperature dependence of resistivity that can be explained within the band conduction model. The calculated activation energies range from 0.169 eV to 0.187 eV, depending on the crystallographic direction and thermal history of the sample.
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Affiliation(s)
- Bolesław Barszcz
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznań 60-179, Poland.
| | - Tetiana N Starodub
- Institute of Chemistry, Jan Kochanowski University, 25-405 Kielce, Poland
| | - Adam Mizera
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznań 60-179, Poland
| | - Roman Świetlik
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, Poznań 60-179, Poland
| | - Karol Rytel
- Faculty of Material Engineering and Technical Physics, Poznan University of Technology, Piotrowo 3, 60-965 Poznań, Poland
| | - Viktor O Iaroshenko
- Department of Chemistry, University of Helsinki, A.J. Virtasen aukio 1, 00014 Helsinki, Finland; Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovkého 40, 97401 Banska Bystrica, Slovakia
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Olejniczak I, Barszcz B, Auban-Senzier P, Jeschke HO, Wojciechowski R, Schlueter JA. Charge-Ordering and Structural Transition in the New Organic Conductor δ'-(BEDT-TTF) 2CF 3CF 2SO 3. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:1890-1900. [PMID: 35145572 PMCID: PMC8819691 DOI: 10.1021/acs.jpcc.1c09458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/11/2022] [Indexed: 06/14/2023]
Abstract
We report structural, transport, and optical properties and electronic structure calculations of the δ'-(BEDT-TTF)2CF3CF2SO3 (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) organic conductor that has been synthesized by electrocrystallization. Electronic structure calculations demonstrate the quasi-one-dimensional Fermi surfaces of the compound, while the optical spectra are characteristic for a dimer-Mott insulator. The single-crystal X-ray diffraction measurements reveal the structural phase transition at 200 K from the ambient-temperature monoclinic P21/m phase to the low-temperature orthorhombic Pca21 phase, while the resistivity measurements clearly show the first order semiconductor-semiconductor transition at the same temperature. This transition is accompanied by charge-ordering as it is confirmed by splitting of charge-sensitive vibrational modes observed in the Raman and infrared spectra. The horizontal stripe charge-order pattern is suggested based on the crystal structure, band structure calculations, and optical spectra.
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Affiliation(s)
- Iwona Olejniczak
- Institute
of Molecular Physics, Polish Academy of
Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
| | - Bolesław Barszcz
- Institute
of Molecular Physics, Polish Academy of
Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
| | - Pascale Auban-Senzier
- Laboratoire
de Physique des Solides, Université Paris-Saclay, UMR 8502
CNRS, Université Paris-Sud, Orsay 91405, France
| | - Harald O. Jeschke
- Research
Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Roman Wojciechowski
- Department
of Molecular Physics, Faculty of Chemistry, Technical University of Łódź, Żeromskiego 116, 90-924 Łódź, Poland
| | - John A. Schlueter
- Materials
Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Division
of Materials Research, National Science
Foundation, 2415 Eisenhower
Avenue, Alexandria, Virginia 22314, United States
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Iwai S, Kawakami Y, Itoh H, Yonemitsu K. Petahertz charge dynamics in a correlated organic superconductor. Faraday Discuss 2022; 237:353-367. [DOI: 10.1039/d2fd00004k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an observation of stimulated emission induced by a nearly single-cycle 6 fs near infrared electric field of 10 MV/cm in an organic superconductor (κ-(h-ET)2Cu[N(CN)2]Br). The stimulated emission is...
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Abstract
This short review article provides the reader with a summary of the history of organic conductors. To retain a neutral and objective point of view regarding the history, background, novelty, and details of each research subject within this field, a thousand references have been cited with full titles and arranged in chronological order. Among the research conducted over ~70 years, topics from the last two decades are discussed in more detail than the rest. Unlike other papers in this issue, this review will help readers to understand the origin of each topic within the field of organic conductors and how they have evolved. Due to the advancements achieved over these 70 years, the field is nearing new horizons. As history is often a reflection of the future, this review is expected to show the future directions of this research field.
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Revelli Beaumont M, Hemme P, Gallais Y, Sacuto A, Jacob K, Valade L, de Caro D, Faulmann C, Cazayous M. Possible observation of the signature of the bad metal phase and its crossover to a Fermi liquid in κ-(BEDT-TTF) 2Cu(NCS) 2 bulk and nanoparticles by Raman scattering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:125403. [PMID: 33463531 DOI: 10.1088/1361-648x/abd813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
κ-(BEDT-TTF)2Cu(NCS)2 has been investigated by Raman scattering in both bulk and nanoparticle compounds. Phonon modes from 20 to 1600 cm-1 have been assigned. Focusing on the unexplored low frequency phonons, a plateau in frequencies is observed in the bulk phonons between 50 and 100 K and assigned to the signature of the bad metal phase. Nanoparticles of κ-(BEDT-TTF)2Cu(NCS)2 exhibit anomalies at 50 K associated to the crossover from a bad metal to a Fermi liquid whose origins are discussed.
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Affiliation(s)
- M Revelli Beaumont
- Laboratoire Matériaux et Phénomènes Quantiques (UMR 7162 CNRS), Université de Paris, 75205 Paris Cedex 13, France. Laboratoire de Chimie de Coordination (UPR 8241), Université Paul Sabatier Toulouse, France
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Zhilyaeva EI, Drichko NV, Shilov GV, Flakina AM, Torunova SA, Lyubovskaya R. Optical Study of Anisotropy in Organic Conductors D4[MBr4](Solvent). RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2020. [DOI: 10.1134/s0036024420050301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Band Structure and Physical Properties of α-STF2I3: Dirac Electrons in Disordered Conduction Sheets. CRYSTALS 2020. [DOI: 10.3390/cryst10040270] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The compound being investigated is an organic charge-transfer complex of the unsymmetrical donor STF with I3 [STF = bis(ethylenedithio)diselenadithiafulvalene], which is isostructural with α-ET2I3 and α-BETS2I3 [ET = bis(ethylenedithio)tetrathiafulvalene, BETS = bis(ethylenedithio)tetraselenafulvalene]. According to recent studies, the calculated band structure should represent a zero-gap semiconductor at 1 bar that is similar to α-ET2I3 under high pressure (>15 kbar). Such materials have attracted extensive interest because the electrons at the Fermi level can be massless Dirac fermions (MDFs), with relativistic behaviors like those seen in graphene. In fact, α-STF2I3 exhibited nearly temperature-independent resistivity, ρ, (~100–300 K), a phenomenon that is widely observed in zero-gap semiconductors. The non-Arrhenius-type increase in ρ (<~100 K) was consistent with the characteristics of interacting MDFs. The paramagnetic susceptibility, χ, (2–300 K)—as well as the reflectivity, R and optical conductivity, σ, (25–300 K; 400–25,000 cm−1)—were also almost temperature independent. Furthermore, σ was practically independent of wavenumber at ~6000–15,000 cm−1. There was no structural transition based on X-ray studies (90–300 K). Considering all the electrical, magnetic, optical and structural properties of α-STF2I3 at 1 bar, it was concluded that the salt possesses a band structure characterized with Dirac cones, which was consistent with the calculation.
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Frąckowiak A, Świetlik R, Jeannin O, Fourmigué M, Li W, Dressel M. Charge localization in 1D tetramerized organic conductors: the special case of (tTTF) 2ClO 4. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:155601. [PMID: 30669131 DOI: 10.1088/1361-648x/ab00b5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report a detailed structural and spectroscopic study of the 1D 2:1 cation radical salt (tTTF)2ClO4, where tTTF = trimethylenetetrathiafulvalene, which exhibits a semiconductor-semiconductor phase transition at ca. T = 137 K. Crystal structures are determined above and below the transition; the tTTF molecules in stacks are grouped into weakly interacting tetramers. The reorganization of tTTF stacks is accompanied with an order-disorder transition in anion sublattice. Polarized infrared and Raman spectra of (tTTF)2ClO4 are measured in the broad frequency range as a function of the temperature (10-293 K). The structural and vibrational features are investigated to elucidate the origin of the semiconductor-semiconductor phase transition. We discuss the electron-intramolecular vibration coupling effects in the vibrational spectra of (tTTF)2ClO4 and identify signatures of high- and low-temperature states of charge localization in the tetramerized system. Both the C=C and C-S stretching modes of tTTF give evidence of strong charge distribution fluctuations in conducting stacks for T > 137 K, which are responsible for the appearance of molecules with charge +1e, and charge localization in tTTF tetramers for T < 137 K. The uniqueness of the salt (tTTF)2ClO4 in comparison with other tetramerized 1D systems is discussed.
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Affiliation(s)
- Arkadiusz Frąckowiak
- Institute of Molecular Physics, Polish Academy of Sciences, ul. Mariana Smoluchowskiego 17, 60-179 Poznań, Poland
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Hu Y, Zhong G, Guan YS, Armstrong JN, Li C, Liu C, N'Diaye A, Bhattacharya A, Ren S. Strongly Correlated Aromatic Molecular Conductor. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1900299. [PMID: 30786158 DOI: 10.1002/smll.201900299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/11/2019] [Indexed: 06/09/2023]
Abstract
Strongly correlated electronic molecules open the way for strong coupling between charge, spin, and lattice degrees of freedom to enable interdisciplinary fields, such as molecular electronic switches and plasmonics, spintronics, information storage, and superconducting circuits. However, despite exciting computational predictions and promising advantages to prepare flexible geometries, the electron correlation effect in molecules has been elusive. Here, the electron correlation effects of molecular plasmonic films are reported to uncover their coupling of charge, spin, lattice, and orbital for the switchable metal-to-insulator transition under external stimuli, at which the simultaneous transition occurs from the paramagnetic, electrical, and thermal conducting state to the diamagnetic, electrical, and thermal insulating state. In addition, density functional theory calculation and spectroscopic studies are combined to provide the mechanistic understanding of electronic transitions and molecular plasmon resonance observed in molecular conducting films. The self-assembled molecular correlated conductor paves the way for the next generation integrated micro/nanosystems.
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Affiliation(s)
- Yong Hu
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy, Environment & Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Guohua Zhong
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Ying-Shi Guan
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy, Environment & Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Jason N Armstrong
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy, Environment & Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Changning Li
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy, Environment & Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - Changjiang Liu
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Alpha N'Diaye
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Anand Bhattacharya
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Shenqiang Ren
- Department of Mechanical and Aerospace Engineering, Research and Education in Energy, Environment & Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
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Hassan N, Cunningham S, Mourigal M, Zhilyaeva EI, Torunova SA, Lyubovskaya RN, Schlueter JA, Drichko N. Evidence for a quantum dipole liquid state in an organic quasi-two-dimensional material. Science 2018; 360:1101-1104. [PMID: 29880684 DOI: 10.1126/science.aan6286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 05/07/2018] [Indexed: 11/02/2022]
Abstract
Mott insulators are commonly pictured with electrons localized on lattice sites, with their low-energy degrees of freedom involving spins only. Here, we observe emergent charge degrees of freedom in a molecule-based Mott insulator κ-(BEDT-TTF)2Hg(SCN)2Br, resulting in a quantum dipole liquid state. Electrons localized on molecular dimer lattice sites form electric dipoles that do not order at low temperatures and fluctuate with frequency detected experimentally in our Raman spectroscopy experiments. The heat capacity and Raman scattering response are consistent with a scenario in which the composite spin and electric dipole degrees of freedom remain fluctuating down to the lowest measured temperatures.
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Affiliation(s)
- Nora Hassan
- The Institute for Quantum Matter and the Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Streit Cunningham
- The Institute for Quantum Matter and the Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Martin Mourigal
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | | | | | | | - John A Schlueter
- Division of Materials Research, National Science Foundation, Alexandria, VA 22314, USA.,Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Natalia Drichko
- The Institute for Quantum Matter and the Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA.
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Dressel M, Pustogow A. Electrodynamics of quantum spin liquids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:203001. [PMID: 29692367 DOI: 10.1088/1361-648x/aabc1f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Quantum spin liquids attract great interest due to their exceptional magnetic properties characterized by the absence of long-range order down to low temperatures despite the strong magnetic interaction. Commonly, these compounds are strongly correlated electron systems, and their electrodynamic response is governed by the Mott gap in the excitation spectrum. Here we summarize and discuss the optical properties of several two-dimensional quantum spin liquid candidates. First we consider the inorganic material herbertsmithite ZnCu3(OH)6Cl2 and related compounds, which crystallize in a kagome lattice. Then we turn to the organic compounds [Formula: see text]-EtMe3Sb[Pd(dmit)2]2, κ-(BEDT-TTF)2Ag2(CN)3 and κ-(BEDT-TTF)2Cu2(CN)3, where the spins are arranged in an almost perfect triangular lattice, leading to strong frustration. Due to differences in bandwidth, the effective correlation strength varies over a wide range, leading to a rather distinct behavior as far as the electrodynamic properties are concerned. We discuss the spinon contributions to the optical conductivity in comparison to metallic quantum fluctuations in the vicinity of the Mott transition.
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Affiliation(s)
- Martin Dressel
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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14
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Low-Frequency Dynamics of Strongly Correlated Electrons in (BEDT-TTF)2X Studied by Fluctuation Spectroscopy. CRYSTALS 2018. [DOI: 10.3390/cryst8040166] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fluctuation spectroscopy measurements of quasi-two-dimensional organic charge-transfer salts (BEDT-TTF) 2 X are reviewed. In the past decade, the method has served as a new approach for studying the low-frequency dynamics of strongly correlated charge carriers in these materials. We review some basic aspects of electronic fluctuations in solids, and give an overview of selected problems where the analysis of 1 / f -type fluctuations and the corresponding slow dynamics provide a better understanding of the underlying physics. These examples are related to (1) an inhomogeneous current distribution due to phase separation and/or a percolative transition; (2) slow dynamics due to a glassy freezing either of structural degrees of freedom coupling to the electronic properties or (3) of the electrons themselves, e.g., when residing on a highly-frustrated crystal lattice, where slow and heterogeneous dynamics are key experimental properties for the vitrification process of a supercooled charge-liquid. Another example is (4), the near divergence and critical slowing down of charge carrier fluctuations at the finite-temperature critical endpoint of the Mott metal-insulator transition. Here also indications for a glassy freezing and temporal and spatial correlated dynamics are found. Mapping out the region of ergodicity breaking and understanding the influence of disorder on the temporal and spatial correlated fluctuations will be an important realm of future studies, as well as the fluctuation properties deep in the Mott or charge-ordered insulating states providing a connection to relaxor or ordered ferroelectric states studied by dielectric spectroscopy.
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Li W, Rose E, Tran MV, Hübner R, Łapiński A, Świetlik R, Torunova SA, Zhilyaeva EI, Lyubovskaya RN, Dressel M. The metal-insulator transition in the organic conductor β ″-(BEDT-TTF) 2Hg(SCN) 2Cl. J Chem Phys 2017; 147:064503. [PMID: 28810750 DOI: 10.1063/1.4997198] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We explore the nature of the metal-insulator transition in the two-dimensional organic compound β″-(BEDT-TTF)2Hg(SCN)2Cl by x-ray, electrical transport, ESR, Raman, and infrared investigations. Magnetic and vibrational spectroscopy concurrently reveal a gradual dimerization along the stacking direction (a-b), setting in already at the crossover temperature of 150 K from the metallic to the insulating state. A spin gap of Δσ=47 meV is extracted. From the activated resistivity behavior below T = 55 K, a charge gap of Δρ=60 meV is derived. At TCO = 72 K, the C=C vibrational modes reveal the development of a charge-ordered state with a charge disproportionation of 2δρ=0.34e. In addition to a slight structural dimerization, charge-order causes stripes most likely perpendicular to the stacks.
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Affiliation(s)
- Weiwu Li
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Eva Rose
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Minh Vu Tran
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Ralph Hübner
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Andrzej Łapiński
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
| | - Roman Świetlik
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
| | - Svetlana A Torunova
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142 432 Chernogolovka, Russia
| | - Elena I Zhilyaeva
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142 432 Chernogolovka, Russia
| | - Rimma N Lyubovskaya
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 142 432 Chernogolovka, Russia
| | - Martin Dressel
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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Löhle A, Rose E, Singh S, Beyer R, Tafra E, Ivek T, Zhilyaeva EI, Lyubovskaya RN, Dressel M. Pressure dependence of the metal-insulator transition in κ-(BEDT-TTF) 2Hg(SCN) 2Cl: optical and transport studies. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:055601. [PMID: 27958198 DOI: 10.1088/1361-648x/29/5/055601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The two-dimensional organic conductor κ-(BEDT-TTF)2-Hg(SCN)2Cl exhibits a pronounced metal-insulator transition at [Formula: see text] K. From the splitting of the molecular vibrations, the phase transition can be unambiguously assigned to charge-ordering with [Formula: see text]. We have investigated the pressure evolution of this behavior by temperature-dependent electrical transport measurements and optical investigations applying hydrostatic pressure up to 12 kbar. The data reveal a mean-field like down-shift of [Formula: see text] with a critical pressure of [Formula: see text] kbar and a metallic state above the suppression of the charge-ordered state; no traces of superconductivity could be identified down to T = 1.5 K. As the charge order [Formula: see text] sets in abruptly with decreasing temperature, its size remains unaffected by pressure. However, the fraction of charge imbalanced molecules decreases until it is completely absent above 1.6 kbar.
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Affiliation(s)
- A Löhle
- Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
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Infrared Investigations of the Neutral-Ionic Phase Transition in TTF-CA and Its Dynamics. CRYSTALS 2017. [DOI: 10.3390/cryst7010017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Beyer R, Dressel M. Piston pressure cell for low-temperature infrared investigations. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:053904. [PMID: 26026533 DOI: 10.1063/1.4920921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The design of a piston pressure cell ranging up to approximately 11 kilobars is reported, which allows for optical reflection measurements in the infrared spectral range from 100 to 8000 cm(-1) down to temperatures as low as 6 K. The mechanical alignment and vacuum considerations are discussed before details of the sample preparation are given, with particular emphasis on small and fragile single crystals, mosaics, and pressed powder. A few examples of one- and two-dimensional organic conductors illustrate the performance.
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Affiliation(s)
- R Beyer
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - M Dressel
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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19
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Dengl A, Beyer R, Peterseim T, Ivek T, Untereiner G, Dressel M. Evolution of ferroelectricity in tetrathiafulvalene-p-chloranil as a function of pressure and temperature. J Chem Phys 2014; 140:244511. [PMID: 24985658 DOI: 10.1063/1.4884964] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Armin Dengl
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Rebecca Beyer
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Tobias Peterseim
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Tomislav Ivek
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Gabriele Untereiner
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Martin Dressel
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
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20
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Gao F, Zhu FF, Wang XY, Xu Y, Wang XP, Zuo JL. Stabilizing Radical Cation and Dication of a Tetrathiafulvalene Derivative by a Weakly Coordinating Anion. Inorg Chem 2014; 53:5321-7. [DOI: 10.1021/ic5006117] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Feng Gao
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Nanjing National Laboratory
of Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Fei-Fei Zhu
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Nanjing National Laboratory
of Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Xing-Yong Wang
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Nanjing National Laboratory
of Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Yan Xu
- College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing, 210009, P. R. China
| | - Xin-Ping Wang
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Nanjing National Laboratory
of Microstructures, Nanjing University, Nanjing 210093, P. R. China
| | - Jing-Lin Zuo
- State Key Laboratory of Coordination Chemistry,
School of Chemistry and Chemical Engineering, Nanjing National Laboratory
of Microstructures, Nanjing University, Nanjing 210093, P. R. China
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21
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Abbaz T, Bendjeddou A, Gouasmia A, Villemin D, Shirahata T. New unsymmetrically benzene-fused bis (tetrathiafulvalene): synthesis, characterization, electrochemical properties and electrical conductivity of their materials. Int J Mol Sci 2014; 15:4550-64. [PMID: 24642878 PMCID: PMC3975413 DOI: 10.3390/ijms15034550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 11/16/2022] Open
Abstract
The synthesis of new unsymmetrically benzene-fused bis (tetrathiafulvalene) has been carried out by a cross-coupling reaction of the respective 4,5-dialkyl-1,3-dithiole-2-selenone 6-9 with 2-(4-(p-nitrophenyl)-1,3-dithiole-2-ylidene)-1,3,5,7-tetrathia-s-indacene-6-one 5 prepared by olefination of 4-(p-nitrophenyl)-1,3-dithiole-2-selenone 3 and 1,3,5,7-tetrathia-s-indacene-2,6-dione 4. The conversion of the nitro moiety 10a-d to amino 11a-d then dibenzylamine 12a-d groups respectively used reduction and alkylation methods. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV) technique. Charge transfer complexes with tetracyanoquino-dimethane (TCNQ) were prepared by chemical redox reactions. The complexes have been proven to give conducting materials.
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Affiliation(s)
- Tahar Abbaz
- Laboratory of Aquatic and Terrestrial Ecosystems, Organic and Bioorganic Chemistry Group, University of Mohammed Cherif Mesaadia, Souk Ahras 41000, Algeria.
| | - Amel Bendjeddou
- Laboratory of Aquatic and Terrestrial Ecosystems, Organic and Bioorganic Chemistry Group, University of Mohammed Cherif Mesaadia, Souk Ahras 41000, Algeria.
| | - Abdelkrim Gouasmia
- Laboratory of Organic Materials and Heterochemistry, University of Tebessa, Constantine Road, Tebessa 12000, Algeria.
| | - Didier Villemin
- Laboratory of Molecular and Thio-Organic Chemistry, UMR CNRS 6507, INC3M, FR 3038, Labex EMC3, ENSICAEN & University of Caen, Caen 14050, France.
| | - Takashi Shirahata
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehine University, 3 Bunkyo-cho, Matsuyama, Ehine 790-8577, Japan.
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22
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Peterseim T, Antal Á, Dressel M, Batail P, Drichko N. Characterization of the quasi-one-dimensional compounds δ-(EDT-TTF-CONMe2)2X, X=AsF6 and Br by vibrational spectroscopy and density functional theory calculations. J Chem Phys 2014; 140:064504. [PMID: 24527929 DOI: 10.1063/1.4865106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the infrared spectra of the quarter-filled charge-ordered insulators δ-(EDT-TTF-CONMe2)2X (X= AsF6, Br) along all three crystallographic directions in the temperature range from 300 to 10 K. DFT-assisted normal mode analysis of the neutral and ionic EDT-TTF-CONMe2 molecule allows us to assign the experimentally observed intramolecular modes and to obtain relevant information on the charge ordering and intramolecular interactions. From frequencies of charge-sensitive vibrations we deduce that the charge-ordered state is already present at room temperature and does not change on cooling, in agreement with previous NMR measurements. The spectra taken along the stacking direction clearly show features of vibrational overtones excited due to the anharmonic electronic molecule potential caused by the large charge disproportionation between the molecular sites. The shift of certain vibrational modes indicates the onset of the structural transition below 200 K.
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Affiliation(s)
- Tobias Peterseim
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Ágnes Antal
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Martin Dressel
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Patrick Batail
- Laboratoire MOLTECH, UMR 6200 CNRS-Université d'Angers, Bt. K, UFR Sciences, 2 Boulevard Lavoisier, F-49045 Angers, France
| | - Natalia Drichko
- 1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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23
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Olejniczak I, Frąckowiak A, Świetlik R, Prokhorova TG, Yagubskii EB. Charge fluctuations and ethylene-group-ordering transition in β''-(BEDT-TTF)4[(H3O)Fe(C2O4)3]⋅Y molecular charge-transfer salts. Chemphyschem 2013; 14:3925-35. [PMID: 24203664 DOI: 10.1002/cphc.201300754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Indexed: 11/09/2022]
Abstract
The polarized infrared reflectance and Raman spectra of the three quasi-two-dimensional β''-(BEDT-TTF)4[(H3O)Fe(C2O4)3]⋅Y bifunctional charge-transfer salts, where BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene and Y = C6H5Br, (C6H5CN)0.17(C6H5Br)0.83, (C6H5CN)0.4(C6H5F)0.6, have been measured as a function of the temperature. Signatures of charge inhomogenity have been found in both Raman and infrared spectra of the β''-(BEDT-TTF)4[(H3O)Fe(C2O4)3]⋅Y superconductors. A 100 K transition to a mixed insulating/metallic state is clearly seen for the first time in the temperature dependence of the electronic spectra of superconducting β''-(BEDT-TTF)4[(H3O)Fe(C2O4)3]⋅C6H5Br. We suggest that this phase transition is due to subtle changes in the ethylene groups ordering, which are related to a structural phase transition in the anionic layer. The infrared and Raman spectra of quasi-two-dimensional metal α-'pseudo-κ'-(BEDT-TTF)4[(H3O)Fe(C2O4)3]C6H4Br2 are also investigated.
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Affiliation(s)
- Iwona Olejniczak
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań (Poland).
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24
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Okazaki R, Ikemoto Y, Moriwaki T, Shikama T, Takahashi K, Mori H, Nakaya H, Sasaki T, Yasui Y, Terasaki I. Optical conductivity measurement of a dimer Mott-insulator to charge-order phase transition in a two-dimensional quarter-filled organic salt compound. PHYSICAL REVIEW LETTERS 2013; 111:217801. [PMID: 24313527 DOI: 10.1103/physrevlett.111.217801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 08/12/2013] [Indexed: 06/02/2023]
Abstract
We report a novel insulator-insulator transition arising from the internal charge degrees of freedom in the two-dimensional quarter-filled organic salt β-(meso-DMBEDT-TTF)2PF6. The optical conductivity spectra above Tc=70 K display a prominent feature of the dimer Mott insulator, characterized by a substantial growth of a dimer peak near 0.6 eV with decreasing temperature. The dimer peak growth is rapidly quenched as soon as a peak of the charge order appears below Tc, indicating a competition between the two insulating phases. Our infrared imaging spectroscopy has further revealed a spatially competitive electronic phase far below Tc, suggesting a nature of quantum phase transition driven by material-parameter variations.
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Affiliation(s)
- Ryuji Okazaki
- Department of Physics, Nagoya University, Nagoya 464-8602, Japan
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25
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Ito A, Nakamura Y, Nakamura A, Kishida H. Measurement of the nonlinear conducting states of α-(BEDT-TTF)2I3 using electronic Raman scattering. PHYSICAL REVIEW LETTERS 2013; 111:197801. [PMID: 24266489 DOI: 10.1103/physrevlett.111.197801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 04/22/2013] [Indexed: 06/02/2023]
Abstract
Nonlinear conducting states in a strongly correlated organic electronic system α-(BEDT-TTF)2I3 [BEDT-TTF=bis(ethylenedithio)-tetrathiafulvalene] are studied by Raman spectroscopy. Wide-range Raman spectra of nonlinear conducing states provide direct information about conducting properties through the electronic Raman process. A comparison between the behaviors of the electronic modes of BEDT-TTF layers and the vibrational mode of I3 molecules reveals the formation of nonequilibrium states in which only the electronic parts show the change of states. We obtained a spatial map of the conducting regions of the nonlinear conducting states by utilizing the electronic Raman intensity as a measure of the highly conducting states. A spatially inhomogeneous formation of nonlinear conducting states was observed.
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Affiliation(s)
- Atsuya Ito
- Department of Applied Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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26
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Uji S, Kodama K, Sugii K, Takahide Y, Terashima T, Kurita N, Tsuchiya S, Kohno M, Kimata M, Yamamoto K, Yakushi K. Kosterlitz-Thouless-type transition in a charge ordered state of the layered organic conductor α-(BEDT-TTF)2I3. PHYSICAL REVIEW LETTERS 2013; 110:196602. [PMID: 23705731 DOI: 10.1103/physrevlett.110.196602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Indexed: 06/02/2023]
Abstract
The current-voltage characteristics in the charge order state of the two-dimensional organic conductor α-(BEDT-TTF)(2)I(3) exhibit power law behavior at low temperatures. The power law is understood in terms of the electric-field-dependent potential between electrons and holes, which are thermally excited from the charge order state. The power law exponent steeply changes from 1 to 3 in the range from 30 to 45 K with decreasing temperature, thereby suggesting the occurrence of a Kosterlitz-Thouless-type transition; many (few) unbound electron-hole pairs are thermally excited above (below) the transition. The effects of the finite size and interlayer coupling on the power law behavior are discussed.
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Affiliation(s)
- S Uji
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
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27
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Rose E, Loose C, Kortus J, Pashkin A, Kuntscher CA, Ebbinghaus SG, Hanfland M, Lissner F, Schleid T, Dressel M. Pressure-dependent structural and electronic properties of quasi-one-dimensional (TMTTF)2PF6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:014006. [PMID: 23221131 DOI: 10.1088/0953-8984/25/1/014006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We have performed detailed x-ray investigations of the quasi-one-dimensional organic conductor (TMTTF)(2)PF(6) at room temperature and hydrostatic pressures up to 27 kbar. Based on the pressure-dependent crystal structure, the electronic band structure was calculated by density functional theory (DFT). Our systematic study provides important information on the coupling among the organic molecules but also to the anions. We discuss the consequences for the electronic properties and compare them with optical investigations under pressure. The increasing plasma frequency observed perpendicular to the stacks corresponds to a widening of the bands for the b-direction. Around 20 kbar a dimensional crossover occurs from a one-dimensional Mott insulator to a two-dimensional metal.
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Affiliation(s)
- E Rose
- Physikalisches Institut, Universität Stuttgart, Germany
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28
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Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands. CRYSTALS 2012. [DOI: 10.3390/cryst2031291] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Comprehensive Optical Investigations of Charge Order in Organic Chain Compounds (TMTTF)2X. CRYSTALS 2012. [DOI: 10.3390/cryst2020528] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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30
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Arumugam K, Clark DS, Mague JT, Donahue JP. The dithiolene ligand and tetrathiafulvalene precursor molecules 4,5-bis(bromomethyl)-1,3-dithiol-2-one and 4,5-bis[(dihydroxyphosphoryl)methyl]-1,3-dithiol-2-one. Acta Crystallogr C 2011; 67:o446-9. [PMID: 22051960 DOI: 10.1107/s0108270111040431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 09/30/2011] [Indexed: 11/10/2022] Open
Abstract
The crystal structures of 4,5-bis(bromomethyl)-1,3-dithiol-2-one, C(5)H(4)Br(2)OS(2), (I), and 4,5-bis[(dihydroxyphosphoryl)methyl]-1,3-dithiol-2-one, C(5)H(8)O(7)P(2)S(2), (II), occur with similar unit cells in the same monoclinic space group. Both molecules reside on a twofold symmetry axis coincident with the C=O bond, so that the substituents in the 4- and 5-positions project above and below the plane of the 1,3-dithiol-2-one ring. In both structures, the molecules align themselves in a head-to-tail fashion along the b axis, and these rows of molecules then stack, with alternating directionality, along the c axis. For (II), an extensive network of intermolecular hydrogen bonds occurs between molecules within the same stack and between adjacent stacks. Each -CH(2)P(O)(OH)(2) group participates in four hydrogen bonds, twice as donor and twice as acceptor.
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31
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Dressel M. Quantum criticality in organic conductors? Fermi liquid versus non-Fermi-liquid behaviour. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:293201. [PMID: 21727309 DOI: 10.1088/0953-8984/23/29/293201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Organic metals exhibit unusual electronic properties in their charge and spin degrees of freedom that have puzzled physicists for decades. By now this behaviour is established as intrinsic and related to electronic interactions. Like other correlated electron systems, such as heavy fermions or transition-metal oxides, organic conductors are located next to some ordered phase in the spin or charge sectors. Theory predicts quantum fluctuations to become important at low temperatures and quantum critical behaviour present in most physical properties. Here we survey the experimental evidence of quantum criticality in well-established organic model compounds and look for indications of non-Fermi-liquid behaviour.
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Affiliation(s)
- Martin Dressel
- Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, Stuttgart, Germany
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32
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Olejniczak I, Łapiński A, Świetlik R, Olivier J, Golhen S, Ouahab L. Experimental and Theoretical Investigation of Vibrational Spectra of Coordination Polymers Based on TCE-TTF. Chemphyschem 2011; 12:2124-30. [DOI: 10.1002/cphc.201100197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Indexed: 11/09/2022]
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33
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Müller J. Fluctuation Spectroscopy: A New Approach for Studying Low‐Dimensional Molecular Metals. Chemphyschem 2011; 12:1222-45. [DOI: 10.1002/cphc.201000814] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Indexed: 11/12/2022]
Affiliation(s)
- Jens Müller
- Institute of Physics, Goethe University Frankfurt, Max‐von‐Laue‐Str. 1, 60438 Frankfurt (M) (Germany), Fax: (+49) 69‐798‐47227
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34
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Kaiser S, Dressel M, Sun Y, Greco A, Schlueter JA, Gard GL, Drichko N. Bandwidth tuning triggers interplay of charge order and superconductivity in two-dimensional organic materials. PHYSICAL REVIEW LETTERS 2010; 105:206402. [PMID: 21231250 DOI: 10.1103/physrevlett.105.206402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Indexed: 05/30/2023]
Abstract
We observe charge-order fluctuations in the quasi-two-dimensional organic superconductor β''-(BEDT-TTF)2SF5CH2CF2SO3, both by means of vibrational spectroscopy, locally probing the fluctuating charge order, and by investigating the in-plane dynamical response by infrared reflectance spectroscopy. The decrease of the effective electronic interaction in an isostructural metal suppresses both charge-order fluctuations and superconductivity, pointing to their interplay. We compare the results of our experiments with calculations on the extended Hubbard model.
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Affiliation(s)
- S Kaiser
- Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
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35
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Zhilyaeva EI, Semkin VN, Yudanova EI, Vlasova RM, Torunova SA, Flakina AM, Mousdis GA, Van KV, Graja A, Lapinski A, Lyubovskii RB, Lyubovskaya RN. Molecular conductors with differently oriented conducting layers, (EDT-TTF)3Hg2Br6 and (TMBEDT-TTF)5Hg(SCN)4-xIx. Russ Chem Bull 2010. [DOI: 10.1007/s11172-010-0247-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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36
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Ivek T, Korin-Hamzić B, Milat O, Tomić S, Clauss C, Drichko N, Schweitzer D, Dressel M. Collective excitations in the charge-ordered phase of α-(BEDT-TTF)2I3. PHYSICAL REVIEW LETTERS 2010; 104:206406. [PMID: 20867047 DOI: 10.1103/physrevlett.104.206406] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Indexed: 05/29/2023]
Abstract
The charge response of a charge-ordered state in the organic conductor α-(BEDT-TTF)2I3 is characterized by dc resistivity, dielectric and optical spectroscopy in different crystallographic directions within the two-dimensional conduction layer. Two dielectric modes are detected. The large mode is related to the phasonlike excitation of the 2k(F) bond-charge density wave which forms in the ab plane. The small dielectric mode is associated with the motion of domain-wall pairs along the a and b axes between two types of domains which are created due to inversion symmetry breaking.
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Affiliation(s)
- T Ivek
- Institut za fiziku, P.O. Box 304, HR-10001 Zagreb, Croatia.
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37
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Abstract
The charge ordered organic salt θ-(BEDT-TTF)2CsZn(SCN)4 exhibits a giant nonlinear conduction at low temperatures. The voltage-current characteristics of this compound are similar to those of a thyristor device, after which we named it the organic thyristor. This material shows current oscillation in the presense of dc voltage, which arises from a mechanism different from conventional oscillating circuits, because the oscillation appears in a sample that does not show negative derivative resistance. We have performed a standard circuit analysis, and show that the voltage-current curve is “blurred” in the high current region, and the oscillation occurs in the blurred region. This type of oscillation has never been reported, and a possible origin for this is suggested.
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38
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Olivier J, Golhen S, Świetlik R, Cador O, Pointillart F, Ouahab L. X‐ray Structures, Spectroscopic and Magnetic Studies of a Coordination Polymer Series Based on a TTF Derivative and Paramagnetic Transition Metals. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200900365] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jean Olivier
- UMR 6226 CNRS‐Université de Rennes 1 “Sciences Chimiques de Rennes”, 263 avenue Général Leclerc, CS 74205, 35042 Rennes cedex, France, Fax: +33‐2‐23236840
| | - Stéphane Golhen
- UMR 6226 CNRS‐Université de Rennes 1 “Sciences Chimiques de Rennes”, 263 avenue Général Leclerc, CS 74205, 35042 Rennes cedex, France, Fax: +33‐2‐23236840
| | - Roman Świetlik
- Institute of Molecular Physics, Polish Academy of Sciences, ul. Mariana Smoluchowskiego 17, 60‐179 Poznan, Poland
| | - Olivier Cador
- UMR 6226 CNRS‐Université de Rennes 1 “Sciences Chimiques de Rennes”, 263 avenue Général Leclerc, CS 74205, 35042 Rennes cedex, France, Fax: +33‐2‐23236840
| | - Fabrice Pointillart
- UMR 6226 CNRS‐Université de Rennes 1 “Sciences Chimiques de Rennes”, 263 avenue Général Leclerc, CS 74205, 35042 Rennes cedex, France, Fax: +33‐2‐23236840
| | - Lahcène Ouahab
- UMR 6226 CNRS‐Université de Rennes 1 “Sciences Chimiques de Rennes”, 263 avenue Général Leclerc, CS 74205, 35042 Rennes cedex, France, Fax: +33‐2‐23236840
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39
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Sasaki T, Yoneyama N. Spatial mapping of electronic states in κ-(BEDT-TTF) 2X using infrared reflectivity. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2009; 10:024306. [PMID: 27877279 PMCID: PMC5090436 DOI: 10.1088/1468-6996/10/2/024306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 07/06/2009] [Accepted: 01/19/2009] [Indexed: 06/03/2023]
Abstract
We review our recent work on spatial inhomogeneity of the electronic states in the strongly correlated molecular conductors κ-(BEDT-TTF)2X. Spatial mapping of infrared spectra (SMIS) is used for imaging the distribution of the local electronic states. In molecular materials, the infrared response of the specific molecular vibration mode with a strong electron-molecular vibration coupling can reflect the electronic states via the change in the vibration frequency. By spatially mapping the frequency shift of the molecular vibration mode, an electronic phase separation has been visualized near the first-order Mott transition in the bandwidth-controlled organic conductor κ-(BEDT-TTF)2Cu[N(CN)2]Br. In addition to reviewing SMIS of the phase separation, we briefly mention the electronic and optical properties of κ-(BEDT-TTF)2X.
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Affiliation(s)
- Takahiko Sasaki
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- JST, CREST, Sanbancho 5, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Naoki Yoneyama
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- JST, CREST, Sanbancho 5, Chiyoda-ku, Tokyo 102-0075, Japan
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40
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Zorina L, Simonov S, Mézière C, Canadell E, Suh S, Brown SE, Foury-Leylekian P, Fertey P, Pouget JP, Batail P. Charge ordering, symmetry and electronic structure issues and Wigner crystal structure of the quarter-filled band Mott insulators and high pressure metals δ-(EDT-TTF-CONMe2)2X, X = Br and AsF6. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b906287d] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Barszcz B, Graja A, Soras G, Keramidas AD, Tasiopoulos AJ, Mousdis GA. Spectral studies of new organic conductor (ETOEDT-PDT-TTF)2I3: Normal mode vibrations of the unsymmetrical π-electron donor. J Mol Struct 2008. [DOI: 10.1016/j.molstruc.2007.12.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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42
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Onda K, Ogihara S, Yonemitsu K, Maeshima N, Ishikawa T, Okimoto Y, Shao X, Nakano Y, Yamochi H, Saito G, Koshihara SY. Photoinduced change in the charge order pattern in the quarter-filled organic conductor (EDO-TTF)2PF6 with a strong electron-phonon interaction. PHYSICAL REVIEW LETTERS 2008; 101:067403. [PMID: 18764502 DOI: 10.1103/physrevlett.101.067403] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2008] [Indexed: 05/26/2023]
Abstract
The quasistable state in the photoinduced phase transition for the quasi-one-dimensional quarter-filled organic conductor (EDO-TTF)2PF6 has been examined by ultrafast reflective measurements and time-dependent model calculations incorporating both electron-electron and electron-phonon interactions. The transient optical conductivity spectrum over a wide probe photon-energy range revealed that photoexcitation induced a new type of charge-disproportionate state. Additionally, coherent and incoherent oscillations dependent on probe photon energies were found, as predicted by the calculation.
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Affiliation(s)
- Ken Onda
- Nonequilibrium Dynamics Project, ERATO/JST, Tsukuba, Ibaraki 305-0801, Japan
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43
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Cauliez P, Mézière C, Auban-Senzier P, Clérac R, Fourmigué M. Square-lattice hybrid organic–inorganic conducting layers in the τ phase of a TTF tertiary amide derivative. NEW J CHEM 2008. [DOI: 10.1039/b801464g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Iwai S, Yamamoto K, Kashiwazaki A, Hiramatsu F, Nakaya H, Kawakami Y, Yakushi K, Okamoto H, Mori H, Nishio Y. Photoinduced melting of a stripe-type charge-order and metallic domain formation in a layered BEDT-TTF-based organic salt. PHYSICAL REVIEW LETTERS 2007; 98:097402. [PMID: 17359195 DOI: 10.1103/physrevlett.98.097402] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Indexed: 05/14/2023]
Abstract
Photoinduced melting of charge-order (CO) in [bis(ethylenedithiolo)]-tetrathiafulvalene (BEDT-TTF) salts was investigated by femotosecond spectroscopy. Comparative studies on two polytypes exhibiting large [theta-(BEDT-TTF)2RbZn(SCN)_{4}] and small [alpha-(BEDT-TTF)2I3] molecular rearrangements through the CO transition were performed. Ultrafast melting of CO for both compounds demonstrates the major contribution of the electronic instability which is due to Coulomb interaction. The roles of the molecular rearrangements on the formation of the CO and the metallic domain are discussed on the basis of low-frequency lattice dynamics.
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Affiliation(s)
- S Iwai
- Department of Physics, Tohoku University, Sendai 980-8578, Japan.
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45
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Schlueter JA, Geiser U, Whited MA, Drichko N, Salameh B, Petukhov K, Dressel M. Two alternating BEDT-TTF packing motifs in α-κ-(BEDT-TTF)2Hg(SCN)3. Dalton Trans 2007:2580-8. [PMID: 17563794 DOI: 10.1039/b701641g] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first BEDT-TTF charge transfer salt in which alternating electron-donor layers possess alpha- and kappa-type packing motifs has been synthesized. The crystal structure and physical properties of the organic conductor alpha-kappa-(BEDT-TTF)2Hg(SCN)3 are described, including a detailed description of its optical properties. The electronic behavior is dominated by a sharp metal-to-insulator transition at T = 176 K which is due to a first-order structural phase transition. The optical properties in the metallic regime are a superposition of those of the alpha- and kappa-phases, while in the insulating state the spectra become more anisotropic in the conducting plane, and the features of the two layers cannot be distinguished.
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Affiliation(s)
- John A Schlueter
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439-4831, USA.
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46
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Shibaeva RP, Khasanov SS, Zorina LV, Simonov SV. Structural features of low-dimensional molecular conductors—Representatives of new hybrid polyfunctional materials: Review. CRYSTALLOGR REP+ 2006. [DOI: 10.1134/s1063774506060058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Merino J, Greco A, Drichko N, Dressel M. Non-fermi liquid behavior in nearly charge ordered layered metals. PHYSICAL REVIEW LETTERS 2006; 96:216402. [PMID: 16803258 DOI: 10.1103/physrevlett.96.216402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Indexed: 05/10/2023]
Abstract
Non-Fermi liquid behavior is shown to occur in two-dimensional metals which are close to a charge ordering transition driven by the Coulomb repulsion. A linear temperature dependence of the scattering rate together with an increase of the electron effective mass occur above T*, a temperature scale much smaller than the Fermi temperature. It is shown that the anomalous temperature dependence of the optical conductivity of the quasi-two-dimensional organic metal alpha-(BEDT-TTF)2MHg(SCN)4, with M = NH4 and Rb, above T* = 50-100K, agrees qualitatively with predictions for the electronic properties of nearly charge ordered two-dimensional metals.
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Affiliation(s)
- J Merino
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid 28049, Spain
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48
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Masino M, Girlando A, Brillante A, Della Valle R, Venuti E, Drichko N, Dressel M. Lattice dynamics of TTF–CA across the neutral–ionic transition. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.08.072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Zhang B, Wang Z, Zhang Y, Takahashi K, Okano Y, Cui H, Kobayashi H, Inoue K, Kurmoo M, Pratt FL, Zhu D. Hybrid Organic−Inorganic Conductor with a Magnetic Chain Anion: κ-BETS2[FeIII(C2O4)Cl2] [BETS = Bis(ethylenedithio)tetraselenafulvalene]. Inorg Chem 2006; 45:3275-80. [PMID: 16602784 DOI: 10.1021/ic051870q] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis, crystal structure, and electrical, optical, and magnetic properties of kappa-BETS2[Fe(III)(C2O4)Cl2], where BETS is bis(ethylenedithio)tetraselenafulvalene, are reported. The black plate crystals consist of parallel donor layers, two per unit cell, displaying a kappa-type packing of BETS(0.5+) within the bc plane and anionic magnetic chains, [Fe(C2O4)Cl2-]n, running along the c axis. It displays metallic behavior down to 4.2 K, and analysis of the optical reflectivity data gives unscreened plasma energies of 0.69 eV (E parallel c) and 0.40 eV (E perpendicular c). The optical anisotropy is larger than that seen for other kappa phases and is described well by transfer integrals obtained from extended Hückel calculations. However, the transfer integrals need to be scaled down uniformly by a factor of 1.21 to reproduce the absolute experimental plasma frequencies. The band structure consists of a one-dimensional (1D) band and a hole pocket, characteristics of kappa phases. The magnetic properties were modeled by the sum of a 1D antiferromagnetic chain contribution from the d spins of Fe3+, a temperature-independent paramagnetic contribution, and a Curie impurity term. At 4.5 K, there is a signature of long-range magnetic ordering to a canted-antiferromagnetic state in the zero-field-cooled-field-cooled magnetizations, and at 2 K, a small hysteresis loop is observed.
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Affiliation(s)
- Bin Zhang
- Organic Solid Laboratory, CMS, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
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50
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Takenaka K, Tamura M, Tajima N, Takagi H, Nohara J, Sugai S. Collapse of coherent quasiparticle states in theta-(BEDT-TTF)2I3 observed by optical spectroscopy. PHYSICAL REVIEW LETTERS 2005; 95:227801. [PMID: 16384266 DOI: 10.1103/physrevlett.95.227801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2004] [Indexed: 05/05/2023]
Abstract
Optical conductivity measurements on the organic metal theta-(BEDT-TTF)2I3 revealed that the system crosses over rapidly from a coherent quasiparticle state to an incoherent state with temperature. Despite the metallic temperature dependence of resistivity, a well-defined Drude peak at low temperatures turns into a far-infrared peak with temperature. The peak energy shifts to higher frequencies and, simultaneously, the spectral weight is transferred to high frequencies beyond the electron band width. These characteristics imply that theta-(BEDT-TTF)2I3, so far believed to be a typical metal, is in fact a strongly correlated electron system with "bad-metal" character.
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Affiliation(s)
- K Takenaka
- RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama 351-0198, Japan.
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