Ferroelectric properties of charge-ordered alpha-(BEDT-TTF)2I3

Abstract

A detailed investigation of the out-of-plane electrical properties of charge-ordered alpha-(BEDT-TTF)2I3 provides clear evidence for ferroelectricity. Similar to multiferroic alpha-(BEDT-TTF)2Cu[N(CN)2]Cl, the polar order in this material is ascribed to the occurrence of bond- and site-centered charge order. Dielectric response typical for relaxor ferroelectricity is found deep in the charge-ordered state. We suggest an explanation in terms of the existence of polar and nonpolar stacks of the organic molecules in this material, preventing long-range ferroelectricity. The results are discussed in relation to the formation or absence of electronic polar order in related charge-transfer salts.

8 pages, 4 figures. Revised version as accepted for publication in Phys. Rev. B

References in corpus (4)

• Charge Ordering in alpha-(BEDT-TTF)2I3 by synchrotron x-ray diffraction
• Absence of charge order in the dimerized κ-phase BEDT-TTF salts
• Absence of polar order in LuFe2O4
• Correlation-driven electronic multiferroicity in (TMTTF)${}_2$-$X$ organic crystals

Cited by in corpus (7)

• Molecular Quantum Materials: Electronic Phases and Charge Dynamics in Two-Dimensional Organic Solids
• Determination of intrinsic ferroelectric polarization in lossy improper ferroelectric systems
• Ingredients for Generalized Models of $\kappa$-Phase Organic Charge-Transfer Salts: A Review
• Anomalous scaling law for thermoelectric transport of 2D-confined electrons in an organic molecular system
• Intriguing relaxor ferroelectricity in a polar CT crystal at the neutral-ionic interface
• Charge glass in an extended dimer Hubbard model
• Third-order Electrical Conductivity of the Charge-ordered Organic Salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$