@article{ReicheBarberkaKnochenhaueretal.1994, author = {Reiche, J{\"u}rgen and Barberka, Thomas Andreas and Knochenhauer, Gerald and Woolley, Martin and Pietsch, Ullrich}, title = {Comprehensive structure investigation and computer modelling of perfluorododecanoic acid multilayers formed by in-vacuo thermal evaporation}, year = {1994}, language = {en} } @article{ReicheDietzelFreydanketal.1995, author = {Reiche, J{\"u}rgen and Dietzel, Birgit and Freydank, Anke-Christine and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig}, title = {Lateral structure of thermally treated oxadiazole Langmuir-Blodgett films}, year = {1995}, language = {en} } @article{ReicheKnochenhauerBarberkaetal.1995, author = {Reiche, J{\"u}rgen and Knochenhauer, Gerald and Barberka, Thomas Andreas and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig and Hodge, P. and Tredgold, Richard H.}, title = {In-plane structure of perfluorotetra decanoic acid Langmuir-Blodgett films and films formed by vacuum deposition}, year = {1995}, language = {en} } @article{ReicheKnochenhauerDieteletal.1997, author = {Reiche, J{\"u}rgen and Knochenhauer, Gerald and Dietel, Reinhard and Freydank, Anke-Christine and Zetzsche, Thomas and Pietsch, Ullrich and Brehmer, Ludwig and Barberka, Thomas Andreas and Geue, Thomas}, title = {Structure of thermally treated oxadiazoleamide Langmuir-Blodgett films}, year = {1997}, abstract = {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.}, language = {en} } @article{ReichePenacoradaGeueetal.1995, author = {Reiche, J{\"u}rgen and Penacorada, Florencio and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig}, title = {In-plane structure of uranylarachidate multilayers}, year = {1995}, language = {en} } @article{ReichePenacoradaGeueetal.1997, author = {Reiche, J{\"u}rgen and Penacorada, Florencio and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig}, title = {Monolayers and multilayers of uranyl arachidate : in-plane structure of uranyl arachidate multilayers}, year = {1997}, abstract = {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.}, language = {en} } @article{ReichePietschFinketal.1992, author = {Reiche, J{\"u}rgen and Pietsch, Ullrich and Fink, Hans-Peter and Lemmetyinen, Helge}, title = {A comparison fo x-ray methods for structure refinement of Langmuir-Blodgett multilayers}, year = {1992}, abstract = {The possibilities and limits of structure refinement of Langmuir-Blodgett films by means of symmetrical reflection of X- rays are described using the example of a stearic acid multilayer. Three different techniques for the determiantion of the electron density profile from reflectivity data are compared; a Fourier method, a Patterson method, and model calculations. The important role of the a priori information for finding the besft structure model is outlined.}, language = {en} } @article{ReinholdGeueHuberetal.2009, author = {Reinhold, Beate and Geue, Thomas and Huber, Patrick and Sant, Tushar and Pietsch, Ullrich and Sztucki, Michael}, title = {In situ and ex situ SAXS investigation of colloidal sedimentation onto laterally patterned support}, issn = {0743-7463}, doi = {10.1021/La803078b}, year = {2009}, abstract = {We report on in situ investigations of colloidal ordering during gravity sedimentation from a colloidal suspension onto a prepatterned support using a polymeric surface relief grating (SRG) as the support. The ordering of colloids with a diameter of 420 nm was investigated by means of grazing-incidence small-angle X-ray scattering (GISAXS) and transmission SAXS using a preparation cell guaranteeing stable temperature and humidity. GISAXS was used for in situ monitoring of the time evolution of colloidal ordering within the whole illuminated sample area. The onset of ordering was indicated by the increase of integrated intensity within a small time frame shortly before complete evaporation of the dispersant. Single domains of coated samples were investigated ex situ by SAXS in transmission geometry where the irradiated sample area was 200 x 200 mu m(2) only. Domains with the typical size of a few millimeters were observed varying in orientation and crystallographic structure for various positions at the sample. They were mainly oriented along the grooves of the grating, confirming the influence of the underlying grating on colloidal ordering.}, language = {en} } @article{RosePietschZeimer1997, author = {Rose, Dirk and Pietsch, Ullrich and Zeimer, Ute}, title = {Characterization of InGaAs single quantum wells buried in GaAs[001] by grazing incidence diffraction}, year = {1997}, language = {en} } @article{SaphiannikovaGeueHennebergetal.2004, author = {Saphiannikova, Marina and Geue, Thomas and Henneberg, Oliver and Morawetz, Knut and Pietsch, Ullrich}, title = {Linear viscoelastic analysis of formation and relaxation of azobenzene polymer gratings}, doi = {10.1063/1.1642606}, year = {2004}, abstract = {Surface relief gratings on azobenzene containing polymer films were prepared under irradiation by actinic light. Finite element modeling of the inscription process was carried out using linear viscoelastic analysis. It was assumed that under illumination the polymer film undergoes considerable plastification, which reduces its original Young's modulus by at least three orders of magnitude. Force densities of about 10(11) N/m(3) were necessary to reproduce the growth of the surface relief grating. It was shown that at large deformations the force of surface tension becomes comparable to the inscription force and therefore plays an essential role in the retardation of the inscription process. In addition to surface profiling the gradual development of an accompanying density grating was predicted for the regime of continuous exposure. Surface grating development under pulselike exposure cannot be explained in the frame of an incompressible fluid model. However, it was easily reproduced using the viscoelastic model with finite compressibility. (C) 2004 American Institute of Physics}, language = {en} }