Multiferroicity in the Mott Insulating Charge-Transfer Salt κ-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl

Abstract

The recently proposed multiferroic state of the charge-transfer salt κ-(BEDT-TTF)${}_2$Cu[N(CN)${}_2$]Cl [P. Lunkenheimer et al., Nature Mater., vol. 11, pp. 755-758, Sept. 2012] has been studied by dc-conductivity, magnetic susceptibility and measurements of the dielectric constant on various, differently prepared single crystals. In the majority of crystals we confirm the existence of an order-disorder-type ferroelectric state which coincides with antiferromagnetic order. This phenomenology rules out scenarios which consider an inhomogeneous, short-range-ordered ferroelectric state. Measurements of the dielectric constant and the magnetic susceptibility on the same crystals reveal that both transitions lie very close to each other or even collapse, indicating that both types of order are intimately coupled to each other. We address issues of the frequency dependence of the dielectric constant ε' and the dielectric loss ε'' and discuss sample-to-sample variations.

7 pages, 7 figures

References in corpus (5)

• Spin current and magneto-electric effect in non-collinear magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Multiferroicity due to charge ordering
• 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 (8)

• 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
• Charge orders in organic charge-transfer salts
• Insights from experiment and $abinitio$ calculations into the glass-like transition in the molecular conductor $\kappa$-(BEDT-TTF)${}_2$Hg(SCN)${}_2$Cl
• 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
• Relaxation dynamics in the one-dimensional organic charge-transfer salt δ-(EDT-TTF-CONMe${}_2$)${}_2$Br