SHORT-RANGE ORDER IN AMORPHOUS POLY(DECYLTHIOPHENES) - A TEMPERATURE-DEPENDENCE STUDY

X-ray diffraction studies have been carried out at various temperatures (300, 200, 100 and 15 K) for poly(3-decylthiophene) (PDT) and poly(4,4'-didecyl-2,2'-bithiophene) (PDDBT), both pristine and doped with FeCl4-. Because of the low crystallinity of all samples, especially for PDDBT, particular attention has been paid to the amorphous component of diffractograms obtained. The temperature dependence of the diffraction spectra gives strong evidence for structural transformation occurring between 300 and 200 K. This transformation is associated with the lowering of the mean intermolecular distance in the polymer, and it is visible both in the amorphous and crystalline components of the diffraction patterns.