The charge-fluctuating and charge-ordered states in metallic, insulating and superconducting bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) salts are characterized through the analysis of the infrared (IR) spectral region relevant to the C––C antisymmetric stretch, b1_nu22.This spectral region shows dramatic changes in band intensity and band-shape by varying the temperature. The observed spectral features can be understood on the basis of an extension of the well-known Kubo model for the spectral signatures of an equilibrium between two states. The two-orders of magnitude increase in the IR oscillator strength of the b1_nu22 mode upon ionization has also to be taken into account.
Spectroscopic characterization of charge-order fluctuations in BEDT-TTF metals and superconductors / Girlando, Alberto; Masino, Matteo; S., Kaiser; Y., Sun; N., Drichko; M., Dressel; H., Mori. - In: PHYSICA STATUS SOLIDI. B, BASIC RESEARCH. - ISSN 1521-3951. - 249:(2012), pp. 953-956. [10.1002/pssb.201100722]
Spectroscopic characterization of charge-order fluctuations in BEDT-TTF metals and superconductors
GIRLANDO, Alberto;MASINO, Matteo;
2012-01-01
Abstract
The charge-fluctuating and charge-ordered states in metallic, insulating and superconducting bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) salts are characterized through the analysis of the infrared (IR) spectral region relevant to the C––C antisymmetric stretch, b1_nu22.This spectral region shows dramatic changes in band intensity and band-shape by varying the temperature. The observed spectral features can be understood on the basis of an extension of the well-known Kubo model for the spectral signatures of an equilibrium between two states. The two-orders of magnitude increase in the IR oscillator strength of the b1_nu22 mode upon ionization has also to be taken into account.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
