Resonance Raman Investigations of Low Energetic Modes in the Organic Superconductors αt-(BEDT-TTF)2I3 and β-(BEDT-TTF)2IAuI |
| T. Ludwig, D. Schweitzer 3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany and H.J. Keller Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany |
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| A study of low energetic modes in the resonance Raman spectra of the organic superconductors αt-(BEDT-TTF)2I3 (Tc = 8 K) and β-(BEDT-TTF)2IAuI (Tc = 4 K) in the temperature range of 1.5-100 K was performed. In both materials, a strong vanishing of low energetic phonon bands (at 30 cm-1 and 40 cm-1 for αt-(BEDT-TTF)2I3 and at 27 cm-1 and 33 cm-1 for β-(BEDT-TTF)2IAuI) below 71 was observed. For the symmetric stretching mode of the I¯3 and the IAuI¯ anion at 120 cm-1 no change below T, was found. In addition, wavelength dependent measurements on α-(BEDT-TTF)2I3 were performed, indicating that the modes around 30 cm-1 are probably librational modes of the BEDT-TTF molecules. |
| DOI: 10.12693/APhysPolA.87.801 PACS numbers: 74.70.Kn, 78.30.-j |