Pressure-dependent optical investigations of Fabre salts in the charge-ordered state. (7th February 2017)

• Record Type: Journal Article
• Authors: Voloshenko, Ievgen; Herter, Melina; Beyer, Rebeca; Pustogow, Andrej; Dressel, Martin
• Is Part Of: Journal of physics. Volume 29:Number 11(2017)
• Publication Date: 2017-02-07
• Subjects: Fabre-salts TMTTF -- charge order -- infrared properties -- spin-Peierls state -- hydrostatic pressure -- phase diagram; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/aa579c
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: In a comprehensive infrared study, the molecular vibrational features of (TMTTF)2 SbF6, (TMTTF)2 AsF6 and (TMTTF)2 PF6 single crystals have been measured down to temperatures as low as 7 K by applying hydrostatic pressure up to 11 kbar. We follow the charge disproportionation below the critical temperatures T CO as pressure increases, and determine the critical pressure values p CO at which the charge-ordered phase is suppressed. The coexistence of the spin-Peierls phase with charge order is explored at low temperatures, and the competition of these two phases is observed. Based on our measurements we construct a generic phase diagram of the Fabre salts with centrosymmetric anions. The pressure-dependent anion and methyl-group dynamics in these quasi-one-dimensional charge transfer compounds yields information about the interplay of the organic molecules in the stacks and the anions, and how this interaction varies upon the transition to the charge-ordered state.