Ordering of PVBA on amorphous SiO2 and Pd(110)

Organic thin films made of 3-trans-2-(pyrid-4-yl-vinyl) benzoic acid are pr oduced by molecular beam deposition under ultra-high vacuum conditions. We demonstrate by optical transmission measurements and second harmonic genera tion that oblique incidence of the molecular beam results in thin films wit h a preferential orientation of the organic molecules on amorphous substrat es. Using Pd(110) as crystalline substrate, our STM images reveal improved ordering due to preferential adsorption at specific lattice sites. (C) 1999 Elsevier Science S.A. All rights reserved.