@article{GeueHennebergPietsch2002, author = {Geue, Thomas and Henneberg, Oliver and Pietsch, Ullrich}, title = {X-ray reflectivity from sinusoidal surface relief gratings}, issn = {0023-4753}, year = {2002}, language = {en} } @article{GeuePietschHaferkornetal.1999, author = {Geue, Thomas and Pietsch, Ullrich and Haferkorn, J. and Stumpe, Joachim and Date, R. W. and Fawcett, A. H.}, title = {Competition of alignment and aggregation? : Phenomena in constrained films of LC poly(olefin ulfone)s and maleic anhydride co- and terpolymers}, year = {1999}, language = {en} } @article{GeueSaphiannikovaHennebergetal.2002, author = {Geue, Thomas and Saphiannikova, Marina and Henneberg, Oliver and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria}, title = {Formation mechanism and dynamics in polymer surface gratings}, year = {2002}, language = {en} } @article{GeueSchultzEnglischetal.1999, author = {Geue, Thomas and Schultz, M. and Englisch, Uwe and St{\"o}mmer, Ralph and Pietsch, Ullrich and Meine, Kerstin and Vollhard, D.}, title = {Investigation of pH-dependent domain structure of fatty acid salt Langmuir-Blodgett films by means of X-ray diffuse scattering and Atomic Force Microscopy}, year = {1999}, language = {en} } @article{GeueStumpePietschetal.1995, author = {Geue, Thomas and Stumpe, Joachim and Pietsch, Ullrich and Haak, M. and Kaupp, G.}, title = {Photochemically induced changes of optical anisotropy and surface of LB-multilayers built up by an amphiphilic and liquid crystalline copolymer conating azobenzene moieties}, year = {1995}, language = {en} } @article{GorfmanTsirelsonPietsch2005, author = {Gorfman, S. V. and Tsirelson, Vladimir G. and Pietsch, Ullrich}, title = {X-ray diffraction by a crystal in a permanent external electric field : general considerations}, issn = {0108-7673}, year = {2005}, abstract = {The variations of X-ray diffraction intensities from a crystal in the presence of a permanent external electric field is modeled analytically using a first-order stationary perturbation theory. The change in a crystal, induced by an external electric field, is separated into two contributions. The first one is related to a pure polarization of an electron subsystem, while the second contribution can be reduced to the displacements of the rigid pseudoatoms from their equilibrium positions. It is shown that a change of the X-ray diffraction intensities mainly originates from the second contribution, while the influence of the pure polarization of a crystal electron subsystem is negligibly small. The quantities restored from an X-ray diffraction experiment in the presence of an external electric field were analyzed in detail in terms of a rigid pseudoatomic model of electron density and harmonic approximation for the atomic thermal motion. Explicit relationships are derived that link the properties of phonon spectra with E-field-induced variations of a structure factor, pseudoatomic displacements and piezoelectric strains. The displacements can be numerically estimated using a model of independent atomic motion if the Debye - Waller factors and pseudoatomic charges are known either from a previous single-crystal X-ray diffraction study or from density functional theory calculations. The above estimations can be used to develop an optimum strategy for a data collection that avoids the measurements of reflections insensitive to the electric-field-induced variations}, language = {en} } @article{GrenzerDarowskiGeueetal.2001, author = {Grenzer, J{\"o}rg and Darowski, Nora and Geue, Thomas and Pietsch, Ullrich and Daniel, A. and Rennon, Siegfried and Reithmaier, Johann-Peter and Forchel, Alfred}, title = {Strain analysis and quantum well intermixing of a laterally modulated multiquantum well system produced by focused ion beam implantation}, year = {2001}, language = {en} } @article{GrenzerDarowskiPietschetal.2000, author = {Grenzer, J{\"o}rg and Darowski, Nora and Pietsch, Ullrich and Daniel, A. and Reithmaier, Johann-Peter and Rennon, Siegfried and Forchel, Alfred}, title = {Grazing-incidence diffraction strain analysis of a laterally-modulated multiquantum well system produced by focused-ion-beam implantation}, year = {2000}, language = {en} } @article{GrenzerSchomburgLingottetal.1998, author = {Grenzer, J{\"o}rg and Schomburg, E. and Lingott, I. and Ignotov, A. a. and Renk, K. F. and Pietsch, Ullrich and Rose, Dirk and Zeimer, Ute and Melzer, B. J. and Ivanov, S. and Schaposchnikov, S. and Kop'ev, P. S. and Pavel'ev, D. G. and Koschurinov, Yu.}, title = {X-ray and transport characterization of an Esaki-Tsu superlattice device}, year = {1998}, language = {en} } @article{HaierHerrmannEsseretal.1998, author = {Haier, P. and Herrmann, B. A. and Esser, N. and Pietsch, Ullrich and L{\"u}ders, K. and Richter, W.}, title = {Influence of the deposition rate on the structure of thin metal layers}, year = {1998}, language = {en} } @article{HennebergChiGeueetal.2001, author = {Henneberg, Oliver and Chi, Li Feng and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria}, title = {Atomic force microscopy inspection of the early state of formation of polymer surface relief grating}, year = {2001}, language = {en} } @article{HennebergGeuePietschetal.2004, author = {Henneberg, Oliver and Geue, Thomas and Pietsch, Ullrich and Winter, Bernd}, title = {Investigation of azobenzene side group orientation in polymer surface relief gratings by means of photoelectron spectroscopy}, year = {2004}, abstract = {The molecular orientation of azobenzene side groups in polymer films before (nonpatterned) and after (patterned) development of a surface relief grating has been investigated by photoelectron spectroscopy using synchrotron radiation. The photoemission spectra obtained for 60-100 eV photons of a patterned and a nonpatterned surface are similar when the polarization vector of the synchrotron light is parallel to the grating vector. However, for perpendicular excitation, considerable spectral intensity differences can be observed for 9-14 eV electron binding energy. The observed changes are attributed to the formation of well-oriented azobenzenes at the surface. (C) 2004 American Institute of Physics}, language = {en} } @article{HennebergGeueSaphiannikovaetal.2003, author = {Henneberg, Oliver and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul}, title = {X-ray and VIS light scattering from light-induced polymer gratings}, doi = {10.1088/0022-3727/36/10A/350}, year = {2003}, language = {en} } @article{HennebergGeueSaphiannikovaetal.2001, author = {Henneberg, Oliver and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria}, title = {Formation and dynamics of polymer surface relief gratings}, issn = {0378-5963}, year = {2001}, language = {en} } @article{HennebergPanznerPietschetal.2004, author = {Henneberg, Oliver and Panzner, Tobias and Pietsch, Ullrich and Geue, Thomas and Saphiannikova, Marina and Rochon, Paul and Finkelstein, Kenneth D.}, title = {X-ray and VIS light scattering from light-induced polymer gratings}, issn = {0044-2968}, year = {2004}, abstract = {Sinusoidally shaped surface relief gratings made of polymer films containing, azobenzene moieties can be created by holographic illumination with laser light of about lambda approximate to 500 nm. The remarkable material transport takes place at temperatures far (100 K) below the glass transition temperature of the material. As probed by visible light scattering the efficiency of grating formation crucially depends on the polarization state of the laser light and is maximal when circular polarization is used. In contrast to VIS light scattering X-ray diffraction is most sensitive for periodic surface undulations with amplitudes below 10 nm. Thus, combined in-situ X-ray and visible light scattering at CHESS were used to investigate the dynamics of surface relief grating formations upon laser illumination. The time development of grating peaks up to 9th order at laser power of P = 20 mW/cm(2) could be investigated, even the onset of grating formation as a function of light polarization. A linear growth of grating amplitude was observed for all polarizations. The growth velocity is maximal using circularly polarized light but very small for s-polarized light}, language = {en} } @article{HennebergPietschPanzneretal.2006, author = {Henneberg, Oliver and Pietsch, Ullrich and Panzner, Tobias and Geue, Thomas and Finkelstein, Kenneth D.}, title = {Simultaneous X-ray and visible light diffraction for the investigation of surface relief and density grating formation in azobenzene containing polymer films}, issn = {1542-1406}, doi = {10.1080/15421400500383345}, year = {2006}, abstract = {The development of surface relief and density patterns in azobenzene polymer films was studied by diffraction at two different wavelengths. We used x-ray diffraction of synchrotron radiation at 0.124 nm in combination with visible light diffraction at a wavelength of 633 nm. In contrast to visible light scattering x-ray diffraction allows the separation of a surface relief and a density grating contribution due to the different functional dependence of the scattering power. Additionally, the x-ray probe is most sensitive for the onset of the surface grating formation}, language = {en} } @article{HennebergRochonPanzneretal.2004, author = {Henneberg, Oliver and Rochon, Paul and Panzner, Tobias and Finkelstein, Kenneth D. and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich}, title = {In-situ Investigation of Surface Relief Grating Formation in Photosensitive Polymers}, year = {2004}, language = {en} } @article{HerrmannKauppGeueetal.1997, author = {Herrmann, A. and Kaupp, G. and Geue, Thomas and Pietsch, Ullrich}, title = {AFM and GID investigations of the gas-solid diazotation of 4-sulfanil-acid-monohydrat single crystals}, year = {1997}, language = {en} } @article{HolyDarhuberStangletal.1999, author = {Hol{\´y}, V{\´a}clav and Darhuber, A. and Stangl, Jochen and Zerlauth, S. and Sch{\"a}ffler, F. and Bauer, G{\"u}nther and Darowski, Nora and L{\"u}bbert, Daniel and Pietsch, Ullrich and Vavra, I.}, title = {HRXRD and GID investigations of a self-organized SiGe quantum dot multilayer}, year = {1999}, language = {en} } @book{HolyPietschBaumbach1999, author = {Hol{\´y}, V{\´a}clav and Pietsch, Ullrich and Baumbach, Tilo}, title = {High-resolution x-ray scattering from thin films and multilayers}, series = {Springer tracts in modern physics}, volume = {149}, journal = {Springer tracts in modern physics}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {3-540-62029-X}, doi = {10.1007/BFb0109385}, pages = {256 S.}, year = {1999}, language = {en} }