Research Abstract |
1. Structural characterization of ultrathin films for fractal immittance device prototypes We have fabricated ultrathin films containing functional molecules aiming to clarify the structure - dielectric property correlations. The atomic force microscopy, the UV-Vis spectroscopy, the X-ray diffraction and other techniques have been adopted for the structural characterization. In the merocyanine-arachidic acid binary mixed LB films, the hydrocarbon chain of an archidic acid molecule is found to be in a nearly all-trans conformation with its axis tending to stand perpendicular to the film surface, and that the chain retains to some extent the freedom of thermal motion, which can be frozen when octadecane is introduced as the third component. Further, we have succeeded in obtaining pure fullerene LB films having an optical density about 3.5 times or more larger than those reported previously. 2. Dielectric characterization of ultrathin films with electrodes We have measured the low-frequency ac conductance of monolayer and multilayer mixed LB films containing merocyanine dye with a pair of A1 electrodes. For three and more layered films, the value of the exponent a of power-law conductivity is found to be less sensitive to the composition and the structure than those for monolayer films. In this respect, novel models have been developed, showing the possibility of controlling the a-value in the wider range.
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