@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{GeueKatholyReicheetal.1998,
  author    = {Geue, Thomas and Katholy, Stefan and Reiche, J{\"u}rgen and Brehmer, Ludwig and Caliebe, W.},
  title     = {Grazing incidence x-ray diffraction (GIXD) measurements of uranyl arachidate (UO2A2) LB films},
  year      = {1998},
  language  = {en}
}
@article{DateFawcettGeueetal.1998,
  author    = {Date, R. W. and Fawcett, A. H. and Geue, Thomas and Haferkorn, J. and Malcolm, R. K. and Stumpe, Joachim},
  title     = {Self-ordering within thin films of poly(olefin sulfone)s.},
  year      = {1998},
  language  = {en}
}
@article{HaferkornGeueDateetal.1998,
  author    = {Haferkorn, J. and Geue, Thomas and Date, R. W. and Fawcett, A. H. and Stumpe, Joachim},
  title     = {Aggregation and orientation phenomena in constrained films of Poly(olefine sulfone)s.},
  year      = {1998},
  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{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{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{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{StoemmerMartinGeueetal.1998,
  author    = {St{\"o}mmer, Ralph and Martin, C. R. and Geue, Thomas and G{\"o}bel, H. and Hub, W. and Pietsch, Ullrich},
  title     = {Comparative studies of fractal parameters of Si(100) surfaces measured by X-ray scattering and atomic force microscopy},
  year      = {1998},
  language  = {en}
}
@article{StahnPucherGeueetal.1998,
  author    = {Stahn, Jochen and Pucher, Andreas and Geue, Thomas and Daniel, A. and Pietsch, Ullrich},
  title     = {Electric field induced electron density response of GaAs and ZnSe},
  year      = {1998},
  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{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{KopecRozpedzikLapoketal.2016,
  author    = {Kopec, Maciej and Rozpedzik, Anna and Lapok, Lukasz and Geue, Thomas and Laschewsky, Andre and Zapotoczny, Szczepan},
  title     = {Stratified Micellar Multilayers-Toward Nanostructured Photoreactors},
  series = {Chemistry of materials : a publication of the American Chemical Society},
  volume    = {28},
  journal   = {Chemistry of materials : a publication of the American Chemical Society},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0897-4756},
  doi       = {10.1021/acs.chemmater.6b00161},
  pages     = {2219 -- 2228},
  year      = {2016},
  abstract  = {Polyelectrolyte multilayers (PEMs) with stratification of the internal structure were assembled from statistical amphiphilic copolyelectrolytes of opposite charges. These polyelectrolytes organize in aqueous solutions into micellar structures with fluoroalkyl and aromatic nanodomains, respectively, that were also preserved after deposition as thin films via layer-by-layer (LbL) electrostatic self-assembly. The unimolecular micelles, formed due to statistical compositions of amphiphilic polyelectrolytes used, were shown to suppress chain interdiffusion between adjacent layers in resulting micellar PEMs, as evidenced by spectroscopic ellipsometry, atomic force microscopy (AFM), and neutron reflectometry (NR) measurements. Additionally, hydrophobic cores of the micelles were used as hosts for photoactive molecules, namely, ferrocene and perfluorinated magnesium phthalocyanine. Stratified micellar multilayers were then deposited as hollow capsules using CaCO3 microparticles as templates. Photoinduced electron transfer (PET) between ferrocene and phthalocyanine solubilized in the polymer micelles was demonstrated to occur efficiently inside the stratified, polyelectrolyte walls of the capsules, due to the polarity gradient created by the incompatible aromatic and fluoroalkyl domains. The obtained results present a new approach to construct well-organized, self-assembled nanostructured materials for solar energy conversion.},
  language  = {en}
}
@article{PoloucekPietschGeueetal.2001,
  author    = {Poloucek, P. and Pietsch, Ullrich and Geue, Thomas and Symietz, Christian and Brezesinski, Gerald},
  title     = {X-ray reflectivity analysis of thin complex Langmuir-Blodgett films},
  year      = {2001},
  language  = {en}
}
@article{PietschGrenzerGeueetal.2001,
  author    = {Pietsch, Ullrich and Grenzer, J{\"o}rg and Geue, Thomas and Neißendorfer, Frank and Brezesinski, Gerald and Symietz, Christian and M{\"o}hwald, Helmuth and Gudat, Wolfgang},
  title     = {The energy dispersive reflectometer at BESSY II : a challenge for thin film analysis},
  issn      = {0167- 5087},
  year      = {2001},
  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{MukhopadhyayDattaSanyaletal.2001,
  author    = {Mukhopadhyay, M. K. and Datta, A. and Sanyal, M. K. and Geue, Thomas and Pietsch, Ullrich},
  title     = {Synchrotron Studies of Melting of Langmuir-Blodgett Films},
  year      = {2001},
  language  = {en}
}
@article{NeumannBuchsteinerMahleretal.2000,
  author    = {Neumann, Werner and Buchsteiner, Alexandra and Mahler, Willy and Geue, Thomas and Pietsch, Ullrich},
  title     = {Dielectric loss spectroscopy at fatty acid salt multilayers},
  year      = {2000},
  abstract  = {Dielectric loss spectroscopy (DLS) was performed at compact samples and lamellary organized Langmuir-Blodgett (LB) films from various fatty acid salts. Previous thermoanalytical measurements at compact samples revealed the appearance of two different phase transition temperatures; the lower one is related to the acid the second one to the acid salt molecules. In spite of ill defined electrical contacts with the film the characteristic DLS frequencies obtained from about 100nm thick multilayer films are similar to those recorded from bulk samples. No significant variations of frequencies were found changing the counter ions. Besides conductivity influence at low frequncies we found two relaxations related to the mobility of the dipolar carboxylat-metal group at about 100 and 10000Hz. One of these frequencies is related to the rotation around the chain axis. The strength of this relaxation increases significantly with increasing the sample temperature above 105°C. This temperature is connected with a structural phase transition observed by X-ray reflectometry. In case of Pb-stearate the results of the dielectric measurements help to interprete this structural change as a transition from an orthorhombic into a free-rotator phase. The uncorrelated rotation of molecules around their molecular axes initiates a much increased relaxation strength at the carboxylat-metal sites.},
  language  = {en}
}
@article{StahnGeueGrenzeretal.2000,
  author    = {Stahn, Jochen and Geue, Thomas and Grenzer, J{\"o}rg and Pietsch, Ullrich},
  title     = {Interaction of short-chain alkanes with surface and interfaces of multilayer films built from amphiphilic molecules: an in-situ X-ray and neutron scattering probe},
  year      = {2000},
  language  = {en}
}
@article{KarcenkoEnglischGrenzeretal.2000,
  author    = {Karcenko, Anatolij V. and Englisch, Uwe and Grenzer, J{\"o}rg and Geue, Thomas and Pietsch, Ullrich and Siebrecht, R.},
  title     = {Investigation of partially deuterated multilayers by means of X-ray and polarized neutron reflectometry},
  issn      = {1044-8632},
  year      = {2000},
  language  = {en}
}
@article{MukherjeeBhattacharyaSanyaletal.2000,
  author    = {Mukherjee, M. and Bhattacharya, M. K. and Sanyal, M. K. and Geue, Thomas and Grenzer, J{\"o}rg and Pietsch, Ullrich},
  title     = {Temperature dependent thickness and surface tension of polymer films},
  isbn      = {81-7371295-6},
  year      = {2000},
  language  = {en}
}
@article{GeueSchultzGrenzeretal.2000,
  author    = {Geue, Thomas and Schultz, Michael and Grenzer, J{\"o}rg and Natansohn, Almeria and Rochon, Paul},
  title     = {X-ray investigations of the molecular mobility with polymer surface gratings},
  year      = {2000},
  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{ReicheFreydankHelmsetal.1999,
  author    = {Reiche, J{\"u}rgen and Freydank, Anke-Christine and Helms, Andreas and Geue, Thomas and Schulz, Burkhard and Brehmer, Ludwig and Stiller, Burkhard and Knochenhauer, Gerald},
  title     = {Vacuum deposition films of oxadiazole compounds : formation and structure investigation},
  year      = {1999},
  abstract  = {The search for alternative routes of organic thin film formation is stimulated by the outstanding properties of these films in such fields as nonlinear optics, photonic data processing and molecular electronics. The formation of highly ordered multilayer structures by thermal vacuum deposition (VD) of organic compounds is an essential step toward the application of supramolecular organic architectures in technical systems. The VD of an amphiphilic substituted 2,5- diphenylene-1,3,4-oxadiazole 1 onto silicon substrates at defined temperature was used for the formation of ultrathin films. The structural data obtained for the VD-films of oxadiazole 1 by means of X-ray reflectivity, X-ray grazing incidence diffraction and atomic force microscopy (AFM) investigations indicate the formation of well ordered oxadiazole multilayers. The structure of the VD-multilayers is compared with that of Langmuir-Blodgett (LB) films and thermally treated LB-multilayers prepared from the same compound.},
  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{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{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{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{StillerGeueMorawetzetal.2005,
  author    = {Stiller, Burkhard and Geue, Thomas and Morawetz, Knut and Saphiannikova, Marina},
  title     = {Optical patterning in azobenzene polymer films},
  issn      = {0022-2720},
  year      = {2005},
  abstract  = {Thin azobenzene polymer films show a very unusual property, namely optically induced material transport. The underlying physics for this phenomenon has not yet been thoroughly explained. Nevertheless, this effect enables one to inscribe different patterns onto film surfaces, including one- and two-dimensional periodic structures. Typical sizes of such structures are of the order of micrometers, i.e. related to the interference pattern made by the laser used for optical excitation. In this study we have measured the mechanical properties of one- and two-dimensional gratings, with a high lateral resolution, using force-distance curves and pulse force mode of the atomic force microscope. We also report on the generation of considerably finer structures, with a typical size of 100 nm, which were inscribed onto the polymer surface by the tip of a scanning near-field optical microscope used as an optical pen. Such inscription not only opens new application possibilities but also gives deeper insight into the fundamentals physics underlying optically induced material transport},
  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}
}
@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{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{HennebergGeueSaphiannikovaetal.2002,
  author    = {Henneberg, Oliver and Geue, Thomas and Saphiannikova, Marina and Natansohn, Almeria and Rochon, Paul and Finkelstein, Kenneth D.},
  title     = {Investigation of material flow on inscribing a polymer surface grating probing X-ray and VIS light scattering},
  issn      = {0927-7757},
  year      = {2002},
  language  = {en}
}
@article{PietschGeueHennebergetal.2003,
  author    = {Pietsch, Ullrich and Geue, Thomas and Henneberg, Oliver and Saphiannikova, Marina},
  title     = {X-ray investigations of formation efficiency of buried azobenzene polymer density gratings},
  doi       = {10.1063/1.1554753},
  year      = {2003},
  language  = {en}
}
@article{StillerKarageorgievGeueetal.2004,
  author    = {Stiller, Burkhard and Karageorgiev, Peter and Geue, Thomas and Morawetz, Knut and Saphiannikova, Marina and Mechau, Norman and Neher, Dieter},
  title     = {Optically induced mass transport studied by scanning near-field optical- and atomic force microscopy},
  issn      = {0204-3467},
  year      = {2004},
  abstract  = {Some functionalised thin organic films show a very unusual property, namely the light induced material transport. This effect enables to generate three-dimensional structures on surfaces of azobenzene containing films only caused by special optical excitation. The physical mechanisms underlying this phenomenon have not yet been fully understood, and in addition, the dimensions of structures created in that way are macroscopic because of the optical techniques and the wavelength of the used light. In order to gain deeper insight into the physical fundamentals of this phenomenon and to open possibilities for applications it is necessary to create and study structures not only in a macroscopic but also in nanometer range. We first report about experiments to generate optically induced nano structures even down to 100 nm size. The optical stimulation was therefore made by a Scanning Near-field Optical Microscope (SNOM). Secondly, physical conditions inside optically generated surface relief gratings were studied by measuring mechanical properties with high lateral resolution via pulse force mode and force distance curves of an AFM},
  language  = {en}
}