T. Ludwig et al., RESONANCE RAMAN INVESTIGATIONS OF THE ELECTRON-PHONON COUPLING IN THEORGANIC SUPERCONDUCTORS BETA-(BEDT-TTF)(2)IAUI AND KAPPA-(BEDT-TTF)(2)I-3, Synthetic metals, 85(1-3), 1997, pp. 1587-1588
We investigated the resonance Raman scattering of the low energetic mo
des of the organic superconductors beta-(BEDT-TTF)(2)IAuI (T-c = 4 K)
and kappa-(BEDT-TTF)(2)I-3 (T-c = 4 K). In the kappa-phase of (BEDT-TT
F)(2)I-3 6 low energetic phonons below 100 cm(-1) exist. No distinct c
hange in the phonon structure occurs on going from the normal to the s
uperconducting state. In the beta-phase of (BEDT-TTF)(2)IAuI only two
phonon modes at 27 cm(-1) and 33 cm(-1) are observed. On cooling from
the normal to the superconducting state the intensity of these modes d
rops by a factor of about 5. Similar effects were already observed in
other beta-phases of organic superconductors.