Oxidation by Iodine Doping

To exclude any possible influences due to the interaction of O2 with polyacetylene and/or I2/ care was taken to avoid any exposure of the samples to air. No metal coating was applied since the value of the macroscopic conductivity of the sample was sufficient for a direct investigation. To overcome the problems associated with the high vapour pressure of iodine at room-temperature and p = 2-10 mbar (loss of o and contamination of the microscope), a commercially available cryo-stage was used, where the sample was kept at 80 K. 

To check for the influence of preparation on the morphology, samples have been investigates, which have been prepared according to fig. 14 before doping. A typical result of this order of preparation is shown in fig. 19. The major difference to the results just described is the clearly discernable string of pearl structure, which is similar to that obtained by preparation of the sample after oxidation with 02- An important difference is the fact that in the latter case, this structure turned out to be induced by preparation. 

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