Structural control of vacuum-deposited thin films by the use of a Langmuir-Blodgett multilayer

Abstract

An amphiphilic diacetylene of heptacosa-10,12-diynoic acid (14-8C) was vacuum deposited on a commercially available glass plate and on 10-layer LB films of both arachidic acid (C 20C) and 14-8C at various substrate temperatures ( T s). At a T s of 22°C, 14-8C molecules on the glass substrate were oriented randomly with respect to the substrate, whereas those on 14-8C LB film at the same T s were all oriented perpendicularly. At the higher T s of 50°C, 14-8C molecules were randomly oriented even on the LB film because of the disordering of molecules in LB films. In the process of structural characterization we have succeeded for the first time in the direct observation of lattice images of LB films by use of a liquid-helium- cooled cryo-electron microscope.