TRANSFORMATION OF (BEDT-TTF)(2)I-3 NETWORKS IN POLYMER-FILMS INTO SUPERCONDUCTING BETA(T) PHASE AS STUDIED BY RESONANT RAMAN-SPECTROSCOPY

Reticulate doped polymer composites containing polyiodide of bis(ethyl enedithio) tetrathiafulvalene (BEDT-TTF or ET) in polycarbonate (PC) f ilms were investigated by resonant Raman spectroscopy (RRS). We found that RRS spectra of non-annealed composites are similar to the spectra of single crystals of the alpha-ET2I3 phase but show also an unexpect ed additional band at 108 cm(-1) due to vibration of the I-3(-) molecu le. The RRS spectra of annealed composites are nearly identical to the spectrum of single crystals of the beta(t)-ET2I3 phase. The reproduci bility of the RRS spectra taken at different spots on the surface of t he composites is very good. Raman microscopy indicated that the surfac e of the composites is homogeneous. (C) 1998 Elsevier Science S.A. All rights reserved.