Structure of β-ET2I3 in conducting polymer films

It is shown by X-ray diffraction studies that polycrystalline β-ET2I3 obtained within a surface layer of polymer film exists in states with different interlayer spacing depending on preparation conditions. The differences of spacing can be as large as 0.1 Å and are due to a stress in polycrystalline layer arising during polymer film solidification. The microcrystallites of β-ET2I3 with larger interlayer spacing can be transformed into equilibrium state with smaller spacing by a treatment of the composite leading to the relaxation of the stress, i.e., annealing or exposure to the vapours of solvent able to swell the polymer. Preliminary studies indicate that the stress in conducting polymer/organic crystals composites has an important influence on their electrical properties.