Neutron and x-ray reflectivity studies of self assembled films prepared by
layer-by-layer adsorption of polyelectrolytes are presented. The films are
prepared from the water soluble deuterated precursor of poly-(p phenylene v
inylene) (d-PPV), poly-(styrene sulfonate) (SPS) and poly (allylamine hydro
chloride) (PAH) followed by thermal treatment. Super lattice structures are
build with single layers of d-PPV separated by two different numbers of SP
S/PAH double layers. In the neutron reflectivity data up to four well prono
unced Bragg peaks show up which can also be seen in x-ray reflectivity as s
mall quasi-Bragg peaks indicating variations in electron density of approx.
5%. From detailed analysis of the data an internal roughness between burri
ed interfaces of approx. 15 A was derived.