Profile structures of very thin multilayers by x-ray diffraction using direct and refinement methods of analysis

Victor Skita, Mark Filipkowski, Anthony F. Garito, J. Kent Blasie
1986 Physical Review B (Condensed Matter)  
Meridional x-ray diffraction data from Langmuir-Blodgett multilayers containing two to ten molecular monolayers of arachidic acid were analyzed by two independent methods. A Patterson function deconvolution technique uniquely provided the electron density profile (8A resolution) of the average, symmetric bilayer repeated in the multilayer. This average bilayer appeared to disorder as the number of bilayers in the multilayer decreased. A refinement technique, which does not assume a
more » ... sume a centrosymmetric structure or the existence of a unit cell, uniquely provided the profile structure of the multilayer itself. In particular it could distinguish the individual monolayers in the multilayer. Meridional x-ray scattering data from Langmuir-Blodgett multilayers composed of arachidic acid and either 'myristic acid or polymerized 10,12 pentacosadiynoic acid were also analyzed by the refinement technique. It found that only the last monolayer in the depostion sequence (ie. the surface monolayer) was disordered and that ordering of the surface monolayer can be induced by the deposition of an additional monolayer. In addition, an application of Langmuir-Blodgett multilayer thin films and their characterization by x-ray scattering is discussed with regards to the structural study of membrane-membrane interactions and the triggering of cellular components of the immune system. Degree Type Dissertation Degree Name
doi:10.1103/physrevb.34.5826 pmid:9940424 fatcat:eub4ddn37ffltgruujzhpc7hu4