X-ray structural study of 4kF Superlattice in (DIDCNQI)2Ag

Nogami, Yasuyuki; Moret, R.; Pouget, J.P.; Yamamoto, Yuichi; Oshima, K.; Hiraki, K.; Kanoda, K.

doi:10.1016/s0379-6779(98)00612-2

Cited by 14 publications

(20 citation statements)

References 4 publications

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“…This means that CO in the TMTTF's is mostly announced by a regime of 3D fluctuations which isotropy reflects the importance of the inter-chain Coulomb coupling. In contrast, regular (i.e., non dimerized) quarter filled systems such as (DIDCNQI) 2 Ag [124] or (o-DMTTF) 2 X [125] exhibit a sizeable regime of 1D 4k F BOW fluctuations above the "CO" transition which in fact presents a mixed CO/DM character.…”

Section: The Underlying Co Instabilitymentioning

confidence: 99%

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Pouget

2012

Crystals

107

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Abstract:We review structural aspects of the Bechgaard and Fabre salts in relationship with their electronic, magnetic and superconducting properties. We emphasize the role of bond and charge modulations of the quarter filled organic stack in the various instabilities and ground states exhibited by these salts. A special consideration is also devoted to the influence of anions and methyl groups in these processes. In particular we point out the importance of the anions in achieving the inter-stack coupling by either direct or indirect (via the polarization of the methyl group cavities) interactions with the donors. In this framework we discuss the role of anions and methyl group disorders in the inhibition of the divergence of the high temperature bond order wave instability of the Bechgaard salts. We analyze the modulation in the magnetic ground states by considering explicitly the coupling of the magnetization with structural degrees of freedom. We consider the role of the anions and methyl groups in stabilizing the charge ordering pattern in the Fabre salts. We also discuss the spin-Peierls transition of the Fabre salts in relation with the charge ordering transition and the adiabaticity of the phonon field. We review the anion ordering transitions by considering more particularly the influence of the ordering process on the electronic structure and on the ground states which results. In this framework we show that the texture of the anion ordered structure has direct consequences on the superconducting properties of (TMTSF) 2 ClO 4 . Finally we conclude on the essential implication of the structural degrees of freedom on the generic phase diagram of the Bechgaard and Fabre salts. OPEN ACCESSCrystals 2012, 2 467

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Section: The Underlying Co Instabilitymentioning

confidence: 99%

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Pouget

2012

Crystals

107

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“…14(a)] can be the fingerprint of these 4k F fluctuations. High-temperature 1D 4k F fluctuations are commonly observed in quarter-filled organic salts based on the TCNQ or DCNQI acceptor derivatives, such as Qn(TCNQ) 2 , 67 (DMe-DCNQI) 2 Ag, 41 and (DI-DCNQI) 2 Ag, 43 or on the TTF or TSF donor derivatives, such as TMTTF-DMTCNQ and TMTSF-DMTCNQ, 62 the only exception being the (TMTTF) 2 X series. 68 These 4k F fluctuations are also systematically observed when the band filling is very close to one-quarter, such as in (TMTTF) 2 Bromanil, 69 DBTTFTCNQCl 2 , 70 BTDMTTF-TCNQ, 71 , and the solid solution (NMP) x (Phen) 1-x TCNQ for x ∼ 0.5.…”

Section: A Pretransitional Effectsmentioning

confidence: 99%

“…In particular, (DMe-DCNQI) 2 Ag (R 1 = R 2 = Me) presents high-temperature 4k F and 2k F structural instabilities, diverging successively into a 4k F order just followed by a 2k F SP-like transition. [40][41][42] The compound (DI-DCNQI) 2 Ag (R 1 = R 2 = I) exhibits also a high-temperature 1D 4k F structural instability diverging into a 4k F order 43 but stabilizes an AF ground state at lower temperature. [44][45][46] However, a recent synchrotron study 33 has revealed the occurrence of a complex 4k F modulation pattern consisting of three types of 4k F order: one with charges on the sites (CO), one with charges on the bonds (DM), and one chain with the presence of charges on both sites and bonds.…”

Section: Introductionmentioning

confidence: 99%

Phase diagram of the correlated quarter-filled-band organic salt series (o-DMTTF)2X(
Foury-Leylekian
¹
,
Auban-Sensier
²
,
Coulon
³

et al. 2011
Phys. Rev. B
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The 2:1 family of organic salts (o-DMTTF) 2 X (X = Cl, Br, I) exhibits regular stacks and a high-symmetry structure, which provide a perfect three-quarter-filling-band system allowing a rich phase diagram in the presence of strong electronic correlations. In this paper, we present a detailed study of this series combining complementary experimental techniques such as resistivity, thermopower, electron spin resonance, static magnetic measurements, and x-ray diffraction. In particular, we show that at ambient pressure (o-DMTTF) 2 X with X = Br and Cl undergoes two successive phase transitions setting successively a 4k F charge density and bond order wave order, then a spin-Peierls (SP) ground state. We discuss the symmetry of these phases and its relationship with the transport and magnetic properties. These phases are also followed under pressure by transport experiments, allowing the establishment of a generic phase diagram for this series of salts, where, with the onset of a one-dimensional to three-dimensional deconfinement transition, the 4k F order vanishes and the SP ground state transforms into a Peierls one. Interestingly, this phase diagram differs significantly from the one previously reported in other three-quarter-filled systems such as (TMTTF) 2 X and δ-(EDT-TTF-CONMe 2 ) 2 X.

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“…It is rewritten as 9) which involves the charge degrees of freedom in both bands but does not involve the spin degrees of freedom.…”

Section: A Electron-electron Interactionsmentioning

confidence: 99%

“…[8] Such an extrinsic potential is absent in the (R 1 R 2 -DCNQI) 2 Ag salts, but the metalinsulator transition occurs, accompanied by the formation of a 4k F CDW for both of the R 1 =R 2 = CH 3 (denoted by DMe hereafter) and R 1 =R 2 =I (denoted by DI hereafter) cases. [9] At low temperatures, (DMe-DCNQI) 2 Ag becomes a spin-Peierls state, while (DI-DCNQI) 2 Ag becomes an antiferromagnet. [10] Thus electron correlation in the π band also plays an essential role to determine the ground-state phases.…”

Section: Introductionmentioning

confidence: 99%

Renormalization-group approach to the metal-insulator transitions in(DCNQI)2M(DCNQI isN,N<

Yonemitsu

1997

Phys. Rev. B

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Metal-insulator transitions and different ground-state phases in quasi-one-dimensional materials, (R1R2-DCNQI)2M (R1=R2=CH3, I and M=Ag, Cu), are studied with a renormalization-group method. We use one-dimensional continuum models with backward scatterings, umklapp processes and couplings with 2kF and 4kF phonons (not static lattice distortion). We take a quarter-filled band for M=Ag and a sixth-filled band coupled with a third-filled band for M=Cu. Depending on electron-electron and electron-phonon coupling strengths, the ground-state phase becomes a Tomonaga-Luttinger liquid or a state with a gap(s). For M=Ag, there appear a spin-gap state with a dominant 2kF charge-density-wave correlation, a Mott insulator with a dominant 4kF chargedensity-wave correlation, or a spin-Peierls state with different magnitudes of spin and charge gaps. Three-dimensionality is taken into account by cutting off the logarithmic singularity in either the particle-particle channel or the particle-hole channel. The difference between the ground-state phase of the R1=R2=CH3 salt (spin-Peierls state) and that of the R1=R2=I salt (antiferromagnetic state) is qualitatively explained by a difference in the cutoff energy in the particle-particle channel. For M=Cu, there appear a Mott insulator with a charge density wave of period 3 and a Peierls insulator with a charge density wave of period 6. The conditions for the experimentally observed, Mott insulator phase are strong correlation in the sixth-filled band, moderate electron-phonon couplings, and finite electron-4kF phonon coupling. Resistance is calculated as a function of temperature with a memory-function approximation in both cases above. It qualitatively reproduces the differences among the M=Ag and M=Cu cases as well as the R1=R2=CH3 and R1=R2=I cases.

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X-ray structural study of 4kF Superlattice in (DIDCNQI)2Ag

Cited by 14 publications

References 4 publications

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Phase diagram of the correlated quarter-filled-band organic salt series (o-DMTTF)2X(
Foury-Leylekian
¹
,
Auban-Sensier
²
,
Coulon
³

et al. 2011
Phys. Rev. B
Self Cite

Renormalization-group approach to the metal-insulator transitions in(DCNQI)2M(DCNQI isN,N<

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X-ray structural study of 4kF Superlattice in (DIDCNQI)2Ag

Cited by 14 publications

References 4 publications

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Structural Aspects of the Bechgaard and Fabre Salts: An Update

Phase diagram of the correlated quarter-filled-band organic salt series (o-DMTTF)2X(Foury-Leylekian1, Auban-Sensier2, Coulon3 et al. 2011Phys. Rev. BSelf Cite

Renormalization-group approach to the metal-insulator transitions in(DCNQI)2M(DCNQI isN,N<

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Resources

About

Phase diagram of the correlated quarter-filled-band organic salt series (o-DMTTF)2X(
Foury-Leylekian
¹
,
Auban-Sensier
²
,
Coulon
³

et al. 2011
Phys. Rev. B
Self Cite