Nonuniform site-charge distribution and fluctuations of charge order in the metallic state of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>α</mml:mi><mml:mtext>−</mml:mtext><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mtext>BEDT-TTF</mml:mtext></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mtext>I</mml:mtext><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>

Yue, Yue; Yamamoto, Kaoru; Uruichi, Mikio; Nakano, Chikako; Yakushi, Kyuya; Yamada, Shigeaki; Hiejima, Toshihiro; Kawamoto, Atsushi

doi:10.1103/physrevb.82.075134

Cited by 59 publications

(86 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yue et al, showed that the linewidth of metallic α-I 3 is about two to three times as large as that of α-NH 4 Hg [130]. As shown in Figure 21a, the linewidth of ν 27 of α-I 3 is much broader than the charge-insensitive mode such as the CH 2 bending mode.…”

Section: Fluctuation Of Charge Order In Metallic Phasementioning

confidence: 88%

“…Recently, Alemany et al, pointed out that the hydrogen bond between the ethylene groups of BEDT-TTF and I 3 − plays an essential role in the CO transition of α-I 3 [129]. In the MI transition of α-I 3 , Raman [111] and infrared [130] spectra showed drastic changes as seen in Figure 18. The assignment of these bands along with vibronic bands was conducted with the aid of 13 C and deuterium substituted compounds.…”

Section: α-(Bedt-ttf) 2 I 3 and Related Compoundsmentioning

confidence: 91%

“…Similar splitting of ν 27 is described in ref. [130]. The crystal of θ-I 3 belongs to the monoclinic system with space group of P2 1 /c, and the unit cell contains four BEDT-TTFs.…”

Section: Assignment In Metallic Phasementioning

confidence: 99%

“…Based on the assignment, it becomes clear that the ν 2 and ν 27 modes are split into two groups, ν 2P and (ν 2R1 , ν 2R2 ) in the Raman spectrum and (ν 27P ) in the infrared spectrum as shown in Figure 18. Applying the linear relationship [46] to the ν 27 mode (50 K), the site charge distribution is estimated as (0.8, 0.7, 0.3, 0.2) [130], which are approximately equal to the values (0.85, 0.80, 0.20, 0.15) estimated by Ivek et al [133]. The CO amplitude (Δρ max = 0.6) is comparable to that of θ-RbZn.…”

Section: α-(Bedt-ttf) 2 I 3 and Related Compoundsmentioning

confidence: 99%

See 3 more Smart Citations

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Yakushi

2012

Crystals

Self Cite

View full text Add to dashboard Cite

This paper reviews charge ordering in the organic conductors, β″-(BEDT-TTF) (TCNQ), θ-(BEDT-TTF) 2 X, and α-(BEDT-TTF) 2 X. Here, BEDT-TTF and TCNQ represent bis(ethylenedithio)tetrathiafulvalene and 7,7,8,8-tetracyanoquinodimethane, respectively. These compounds, all of which have a quarter-filled band, were evaluated using infrared and Raman spectroscopy in addition to optical conductivity measurements. It was found that β″-(BEDT-TTF)(TCNQ) changes continuously from a uniform metal to a chargeordered metal with increasing temperature. Although charge disproportionation was clearly observed, long-range charge order is not realized. Among six θ-type salts, four compounds with a narrow band show the metal-insulator transition. However, they maintain a large amplitude of charge order (Δρ~0.6) in both metallic and insulating phases. In the X = CsZn(SCN) 4 salt with intermediate bandwidth, the amplitude of charge order is very small (Δρ < 0.07) over the whole temperature range. However, fluctuation of charge order is indicated in the Raman spectrum and optical conductivity. No indication of the fluctuation of charge order is found in the wide band X = I 3 salt. In α-(BEDT-TTF) 2 I 3 the amplitude of charge order changes discontinuously from small amplitude at high temperature to large amplitude (Δρ max~0 .6) at low temperature. The long-range chargeordered state shows ferroelectric polarization with fast optical response. The fluctuation of multiple stripes occurs in the high-temperature metallic phase. Among α-(BEDT-TTF) 2 MHg(SCN) 4 (X = NH 4 , K, Rb, Tl), the fluctuation of charge order is indicated only in the X = NH 4 salt. α′-(BEDT-TTF) 2 IBr 2 shows successive phase transitions to the ferroelectric state keeping a large amplitude of charge order (Δρ max~0 .8) over the whole temperature range. It was found that the amplitude and fluctuation of charge order in these compounds is enhanced as the kinetic energy (bandwidth) decreases. OPEN ACCESSCrystals 2012, 2 1292

show abstract

Section: Fluctuation Of Charge Order In Metallic Phasementioning

confidence: 88%

Section: α-(Bedt-ttf) 2 I 3 and Related Compoundsmentioning

confidence: 91%

“…Similar splitting of ν 27 is described in ref. [130]. The crystal of θ-I 3 belongs to the monoclinic system with space group of P2 1 /c, and the unit cell contains four BEDT-TTFs.…”

Section: Assignment In Metallic Phasementioning

confidence: 99%

Section: α-(Bedt-ttf) 2 I 3 and Related Compoundsmentioning

confidence: 99%

See 2 more Smart Citations

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Yakushi

2012

Crystals

Self Cite

View full text Add to dashboard Cite

show abstract

“…Salt with another packing arrangement, α-(BEDT-TTF) 2 X and θ-(BEDT-TTF) 2 X, has been a topic of interest due to the metal-insulator (MI) transition and charge disproportionation by off-site coulomb interaction [22][23][24][25][26][27][28][29]. In this type of organic conductor, various charge disproportionation patterns are realized, and these patterns give important information about the electronic structure.…”

Section: Introductionmentioning

confidence: 99%

Magnetic and Electric Properties of Organic Conductors Probed by 13C-NMR Using Selective-Site Substituted Molecules

2012

Self Cite

View full text Add to dashboard Cite

Quasi-One and quasi-two dimensional organic conductors consisting of TTF derivatives such as BEDT-TTF (bis-(ethylene-dithio)-tetra-thia-fulvalene) and TMTCF (C = S; TMTTF: tetra-methyl-tetra-thia-fulvalene, C = Se; TMTSF: tetra-methyl-tetraselena-fulvalene) have been well investigated in condensed matter physics because of interest in the emerging electric and magnetic properties, such as the spin density wave, charge order, superconductivity, anti-ferromagnetism, and so on. To probe the electronic state, nuclear magnetic resonance (NMR) is one of the most powerful tools as the microscopic magnetometer. A number of 13 C-NMR studies have been performed of the double-site central 13 C= 13C bond substituted molecules. However, problems with the coupled spin system of 13 C= 13 C complicated the interpretation for observations on NMR.Therefore, single-site 13 C-enriched molecules are desired. We summarize the problem of Pake doublet and the preparation of the single-site 13 C-susbstituted BEDT-TTF and TMTCF molecules. We also demonstrate the superiority of 13 C-NMR of the single-site 13 C-susbstituted molecule utilizing the hyperfine coupling tensor.

show abstract

Charge Fluctuations and Ethylene‐Group‐Ordering Transition in β′′‐(BEDT‐TTF)₄[(H₃O)Fe(C₂O₄)₃]⋅Y Molecular Charge‐Transfer Salts

et al. 2013

View full text Add to dashboard Cite

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.

show abstract

Nonuniform site-charge distribution and fluctuations of charge order in the metallic state ofα−(BEDT-TTF)2I3

Cited by 59 publications

References 44 publications

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Magnetic and Electric Properties of Organic Conductors Probed by 13C-NMR Using Selective-Site Substituted Molecules

Charge Fluctuations and Ethylene‐Group‐Ordering Transition in β′′‐(BEDT‐TTF)₄[(H₃O)Fe(C₂O₄)₃]⋅Y Molecular Charge‐Transfer Salts

Contact Info

Product

Resources

About

Nonuniform site-charge distribution and fluctuations of charge order in the metallic state ofα−(BEDT-TTF)2I3

Cited by 59 publications

References 44 publications

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Infrared and Raman Studies of Charge Ordering in Organic Conductors, BEDT-TTF Salts with Quarter-Filled Bands

Magnetic and Electric Properties of Organic Conductors Probed by 13C-NMR Using Selective-Site Substituted Molecules

Charge Fluctuations and Ethylene‐Group‐Ordering Transition in β′′‐(BEDT‐TTF)4[(H3O)Fe(C2O4)3]⋅Y Molecular Charge‐Transfer Salts

Contact Info

Product

Resources

About

Charge Fluctuations and Ethylene‐Group‐Ordering Transition in β′′‐(BEDT‐TTF)₄[(H₃O)Fe(C₂O₄)₃]⋅Y Molecular Charge‐Transfer Salts