TY - JOUR A1 - Englisch, Uwe A1 - Barberka, Thomas Andreas A1 - Pietsch, Ullrich A1 - Höhne, U. T1 - Investigation of the chain-chain interface in a lead-stearate multilayer using neutron reflectivity Y1 - 1995 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Penacorada, Florencio A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - In-plane structure of uranylarachidate multilayers Y1 - 1995 ER - TY - JOUR A1 - Stahn, Jochen A1 - Möhle, Marcus A1 - Pietsch, Ullrich T1 - Accurate structure determination for GaAs using Pendellösung oscillation Y1 - 1996 ER - TY - JOUR A1 - Pietsch, Ullrich A1 - Hansen, N. K. T1 - A critical review of the valence charge density in GaAs Y1 - 1996 ER - TY - JOUR A1 - Lichanot, Albert A1 - Azavant, P. A1 - Pietsch, Ullrich T1 - Ab-initio Hartree-Fock study of the electronic charge density of the cubic boron nitride and its comparison with the experiment Y1 - 1996 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald A1 - Dietel, Reinhard A1 - Freydank, Anke-Christine A1 - Zetzsche, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig A1 - Barberka, Thomas Andreas A1 - Geue, Thomas T1 - Structure of thermally treated oxadiazoleamide Langmuir-Blodgett films N2 - The thermal treatment of Y-type Langmuir-Blodgett (LB) films formed from the amphiphilic derivative of 2,5- diphenyl-1,3,4-oxadiazole 1 results in changes of the molecular packing. These changes have been analysed by a combination of X-ray specular reflectivity data, X-ray grazing incidence diffraction data and scanning force microscopy images, On the basis of these experimental data we have simulated possible supramolecular structures, These simulations provide insight into the intermolecular interactions giving rise to the observed structural transitions. The crystalline structure induced by thermal treatment of the LB films is characterized by a uniaxial texture, which is correlated with the dipping direction during deposition of the LB film. Y1 - 1997 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Penacorada, Florencio A1 - Geue, Thomas A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - Monolayers and multilayers of uranyl arachidate : in-plane structure of uranyl arachidate multilayers N2 - The molecular in-plane structure of uranyl arachidate Langmuir-Blodgett (LB) films formed at different subphase pH values was analysed by means of X-ray grazing-incidence diffraction. For multilayers formed at low subphase pH a reorganisation of the arachidic acid film structure is confirmed. At appropriate subphase pH values, reorganisation of the film structure, e.g. via the formation of three-dimensional crystallites, is prevented by the presence of the uranyl ions and by the subsequent introduction of conformational disorder (gauche defects) in the alkyl chains. The observation of a macroscopic flow-induced in-plane texture in these uranyl arachidate LB films has profound implications for the design of ordered, supramolecular structures by the Langmuir-Blodgett technique. Y1 - 1997 ER - TY - JOUR A1 - Pietsch, Ullrich A1 - Barberka, Thomas Andreas A1 - Geue, Thomas A1 - Stömmer, Ralph T1 - X-ray scattering from thin organic films and multilayers Y1 - 1997 ER - TY - JOUR A1 - Englisch, Uwe A1 - Gutberlet, T. A1 - Seitz, R. A1 - Oeser, R. A1 - Pietsch, Ullrich T1 - Thermally induced rearrangement of fatty acid salt molecules in Langmuir-Blodgett multilayers Y1 - 1997 ER - TY - JOUR A1 - Darowski, Nora A1 - Paschke, K. A1 - Pietsch, Ullrich A1 - Wang, K. H. A1 - Forchel, Alfred A1 - Baumbach, Tilo A1 - Zeimer, Ute T1 - Identification of a buried single quantum well within surface structurized semiconductors using depth resolved x-ray grazing-incidence diffraction Y1 - 1997 ER -