Naslov
Absence of charge order in the dimerized kappa-phase BEDT-TTF salts

Autori
Sedlmeier, K. ; Elsaesser, S. ; Neubauer, D. ; Beyer, Rebecca ; Wu, D. ; Ivek, Tomislav ; Tomić, Silvia ; Schlueter, John A. ; Dressel, Martin

Izvornik
Physical Review B - Condensed Matter and Materials Physics (1098-0121) 86 (2012); 245103-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
charge order; charge disproportionation; 2D organic Mott insulators; infrared vibrational spectroscopy; ferroelectricity

Sažetak
Utilizing infrared vibrational spectroscopy we have investigated dimerized two-dimensional organic salts in oredr to serach for possible charge redistribution that might constitute electronic dipoles and ferroelectricity: the qunatum spin liquid kappa-(BEDT-TTF)2Cu2(CN)3, the antiferromagnetic Mott insulator kappa-(BEDT-TTF)2Cu[N(CN)2]Cl and the superconductor kappa-(BEDT-TTF)2Cu[N(CN)2]Br. None of them exhibit any indication of charge disproportionation. Upon cooling to low temperatures all BEDT-TTF remain homogeneously charged within +/- 0.005e. No modification in the charge distribution is observed around T=6K where a low-temperature anomaly has been reported for the spin liquid material kappa-(BEDT-TTF)2Cu2(CN)3. In this compound the in-plane optical response and vibrational coupling are rather anisotropic, indicating that the tilt of the BEDT-TTF molecules in c-direction and their coupling to the anion layers has to be considered in the explanation of the electromagnetic properties.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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