Relaxor ferroelectricity induced by electron correlations in a molecular dimer Mott insulator

Abstract

We have investigated the dielectric response in an antiferromagnetic dimer-Mott insulator beta'-(BEDT-TTF)2ICl2 with square lattice, compared to a spin liquid candidate kappa-(BEDT-TTF)2Cu2(CN)3. Temperature dependence of the dielectric constant shows a peak structure obeying Curie-Weiss law with strong frequency dependence. We found an anisotropic ferroelectricity by pyrocurrent measurements, which suggests the charge disproportionation in a dimer. The ferroelectric actual charge freezing temperature is related to the antiferromagnetic interaction, which is expected to the charge-spin coupled degrees of freedom in the system.

5 pages, 4 figures, to be published in Phys. Rev. B

References in corpus (3)

• Spin current and magneto-electric effect in non-collinear magnets
• Multiferroicity in an organic charge-transfer salt: Electric-dipole-driven magnetism
• Absence of charge order in the dimerized κ-phase BEDT-TTF salts

Cited by in corpus (21)

• Molecular Quantum Materials: Electronic Phases and Charge Dynamics in Two-Dimensional Organic Solids
• From charge- and spin-ordering to superconductivity in the organic charge-transfer solids
• Evidence for electronically-driven ferroelectricity in the family of strongly correlated dimerized BEDT-TTF molecular conductors
• Dielectric Spectroscopy on Organic Charge-Transfer Salts
• Ferroelectric properties of charge-ordered alpha-(BEDT-TTF)2I3
• Origin of the glass-like dynamics in molecular metals $\kappa$-(BEDT-TTF)${}_{\text{2}}$X: implications from fluctuation spectroscopy and $\text{ab initio}$ calculations
• Polar Charge Fluctuation and Superconductivity in Organic Conductor
• Interplay of dipoles and spins in $\kappa$-(BEDT-TTF)${}_{2}X$, where $X=$ Hg(SCN)${}_2$Cl, Hg(SCN)${}_2$Br, Cu[N(CN)${}_2$]Cl, Cu[N(CN)${}_2$]Br, and Ag${}_2$(CN)${}_3$
• Emergence of charge degrees of freedom under high pressure in an organic dimer-Mott insulator ${\beta }^{\prime }$-(BEDT-TTF)${}_2$ICl${}_2$
• Correlation-driven electronic multiferroicity in (TMTTF)${}_2$-$X$ organic crystals
• Phase coexistence at the first-order Mott-transition revealed by pressure-dependent dielectric spectroscopy of $\kappa$-(BEDT-TTF)${}_2$Cu${}_2$(CN)${}_3$
• Energy Landscape of Charge Excitations in Boundary Region between Dimer-Mott and Charge Order State in Molecular Solids
• Optical Conductivity Measurement of a Dimer-Mott to Charge-Order Phase Transition in a Two-Dimensional Quarter-Filled Organic Salt Compound
• Lattice dynamics coupled to charge and spin degrees of freedom in the molecular dimer-Mott insulator $\kappa$-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl
• Quantum Melting of Magnetic Order in an Organic Dimer-Mott Insulating System
• Phonon-Spectrum Narrowing Induced by Ultrafast Charge Fluctuation in an Organic Dimer Mott Insulator
• Spin and Charge Fluctuations near Metal-Insulator Transition in Dimer-Type Molecular Solid
• Relaxation dynamics in the one-dimensional organic charge-transfer salt δ-(EDT-TTF-CONMe${}_2$)${}_2$Br
• Intriguing relaxor ferroelectricity in a polar CT crystal at the neutral-ionic interface
• Charge glass in an extended dimer Hubbard model
• Thermoelectric transport properties of the quasi-one-dimensional dimer-Mott insulator ${\beta }^{\prime }$-(BEDT-TTF)${}_2$ICl${}_2$