Combined X-ray diffraction, electrical resistivity, and $ab$ $initio$ study of (TMTTF)${}_2$PF${}_6$ under pressure: implications to the unified phase diagram

Abstract

We present a combined experimental and theoretical study on the quasi-one-dimensional organic conductor (TMTTF)${}_2$PF${}_6$, and elucidate the variation of its physical properties under pressure. We fully resolve the crystal structure by single crystal x-ray diffraction measurements using a diamond anvil cell up to 8 GPa, and based on the structural data, we perform first-principles density-functional theory calculations and derive the $ab$ $initio$ extended Hubbard-type Hamiltonians. Furthermore, we compare the behavior of the resistivity measured up to 3 GPa using a BeCu clamp-type cell and the ground state properties of the obtained model numerically calculated by the many-variable variational Monte Carlo method. Our main findings are as follows: i) The crystal was rapidly compressed up to about 3 GPa where the volume drops to 80% and gradually varies down to 70% at 8 GPa. The transfer integrals increase following such behavior whereas the screened Coulomb interactions decrease, resulting in a drastic reduction of correlation effect. ii) The degree of dimerization in the intrachain transfer integrals, as the result of the decrease in structural dimerization together with the change in the intermolecular configuration, almost disappears above 4 GPa; the interchain transfer integrals also show characteristic variations under pressure. iii) The results of identifying the characteristic temperatures in the resistivity and the charge and spin orderings in the calculations show an overall agreement: The charge ordering sensitively becomes unstable above 1 GPa, while the spin ordering survives up to higher pressures. These results shed light on the similarities and differences between applying external pressure and substituting the chemical species (chemical pressure).

13 pages, 10 figures

References in corpus (30)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Optimized norm-conserving Vanderbilt pseudopotentials
• Optimization Algorithm for the Generation of ONCV Pseudopotentials
• Frequency-dependent local interactions and low-energy effective models from electronic structure calculations
• Generalized Lanczos Algorithm for Variational Quantum Monte Carlo
• Charge ordering in the TMTTF family of molecular conductors
• The ferroelectric Mott-Hubbard phase of organic (TMTTF)2X conductors
• Theoretical Aspects of Charge Ordering in Molecular Conductors
• Electronic Structure Calculation by First Principles for Strongly Correlated Electron Systems
• Transport criticality of the first-order Mott transition in a quasi-two-dimensional organic conductor, $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl
• RESPACK: An ab initio tool for derivation of effective low-energy model of material
• Competition and coexistence of bond and charge orders in (TMTTF)2AsF6
• mVMC - Open-source software for many-variable variational Monte Carlo method
• Electron-lattice coupling and the broken symmetries of the molecular salt (TMTTF)${}_2$SbF${}_6$
• Ab initio two-dimensional multiband low-energy models of EtMe_3Sb[Pd(dmit)_2]_2 and κ-(BEDT-TTF)_2Cu(NCS)_2 with comparisons to single-band models
• Comprehensive transport studies of anisotropy and ordering phenomena in quasi-one-dimensional (TMTTF)2X salts (X = PF6, AsF6, SbF6; BF4, ClO4, ReO4)
• From spin-Peierls to superconductivity: (TMTTF)_2PF_6 under high pressure
• Mott Transition and Phase Diagram of $\kappa$-(BEDT-TTF)2Cu(NCS)2 Studied by Two-Dimensional Model Derived from Ab initio Method
• Tuning the magnetic dimensionality by charge ordering in the molecular TMTTF salts
• Electronic properties of Fabre charge-transfer salts under various temperature and pressure conditions
• Odd-frequency pairing in (TMTSF)2ClO4
• Ab initio Low-Dimensional Physics Opened Up by Dimensional Downfolding: Application to LaFeAsO
• Unconventional dual 1D-2D quantum spin liquid revealed by $ab$ $initio$ studies on organic solids family
• Electronic Correlation and Geometrical Frustration in Molecular Solids -- A Systematic ab initio Study of ${\beta }^{\prime }$-$X$[Pd(dmit)${}_2$]${}_2$
• $Ab$ $initio$ derivation and exact-diagonalization analysis of low-energy effective Hamiltonians for ${\beta }^{\prime }$-X[Pd(dmit)${}_2$]${}_2$
• Comprehensive $ab$ $initio$ investigation of the phase diagram of quasi-one-dimensional molecular solids
• Gap opening mechanism for correlated Dirac electrons in organic compounds $\alpha$-(BEDT-TTF)${}_2$I${}_3$ and $\alpha$-(BEDT-TSeF)${}_2$I${}_3$
• Pressure-induced structural phase transition in the Bechgaard-Fabre salts
• Spin frustration, charge ordering, and enhanced antiferromagnetism in TMTTF${}_2$SbF${}_6$
• H-wave -- A Python package for the Hartree-Fock approximation and the random phase approximation

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