The paper points out the importance of the coupling between anions and donors in order to achieve the 4k F charge localization observed in (TMTTF) 2PF 6, δ-(EDT-TTF-CONMe 2) 2Br and (o-DMTTF) 2Cl/Br salts, the 2k F charge density wave (CDW) ground state of α-(BEDT-TTF) 2KHg(SCN) 4 and the metal to insulator transition of α-(BEDT-TTF) 2I 3. This coupling leads to a cooperative displacement wave of the anions accompanied by a modulation of the density of π holes on the donors. We distinguish two principal anion-donor coupling mechanisms: a direct mechanism via the Hartree anion potential on donor sites and an indirect mechanism via the polarization of σ bonds activated by the modification of the H bonds network. Both kinds of interaction are tuned by the relative displacement of the anions with respect to the donors. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
|Journal||Physica Status Solidi (B) Basic Research|
|Publication status||Published - 1 May 2012|
- Anion-donor interactions
- Charge density waves
- Charge ordering
- Organic conductors