@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{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{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{GeueHennebergGrenzeretal.2002, author = {Geue, Thomas and Henneberg, Oliver and Grenzer, J{\"o}rg and Pietsch, Ullrich and Natansohn, Almeria and Rochon, Paul and Finkelstein, Kenneth D.}, title = {Formation of a buried density grating on thermal erasure of azobenzene polymer surface gratings}, issn = {0927-7757}, year = {2002}, 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} } @phdthesis{Henneberg2004, author = {Henneberg, Oliver}, title = {In-situ Untersuchungen zur Entstehung von Oberfl{\"a}chengittern in Polymeren}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001331}, school = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {In festen azobenzenhaltigen Polymeren wurde bei Bestrahlung mit blauem Licht ein makroskopischer Materialtransport beobachtet. Um die Dynamik der Gitterentstehung zu verfolgen, wurde am Speicherring f{\"u}r Synchrotronstrahlung ein Gitterschreibaufbau errichtet. Damit konnte erstmals in dieser Arbeit die Gitterbildungsgeschwindigkeit in-situ simultan mit R{\"o}ntgen- und Lichtstreuung untersucht werden. Mit Hilfe einer speziellen Anpassung der R{\"o}ntgenstreutheorie konnten sehr gute {\"U}bereinstimmungen von theoretischen Berechnungen mit den Messergebnissen erzielt werden. Dabei konnte nachgewiesen werden, dass sich zeitgleich mit einem Oberfl{\"a}chengitter auch ein Dichtegitter entwickelt. Durch die Trennung beider Streuanteile ließ sich die Dynamik der Strukturentstehungen bestimmen. Des weiteren konnte erstmals mit Hilfe der Photoelektronenspektroskopie die molekulare Orientierung an der Oberfl{\"a}che eines Oberfl{\"a}chengitters nachgewiesen werden. Die Bewegungsursache kann auf einen Impuls{\"u}bertrag w{\"a}hrend der Isomerisierung zur{\"u}ckgef{\"u}hrt werden, w{\"a}hrend die Bewegungsrichtung durch den elektrischen Feldvektor festgelegt wird. Die Theorie der Gitterentstehung konnte verbessert werden.}, language = {de} } @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.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{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{PietschSaphiannikovaHennebergetal.2004, author = {Pietsch, Ullrich and Saphiannikova, Marina and Henneberg, Oliver and Geue, Thomas}, title = {Non-linear effects during inscription of azobenzene surface relief gratings}, year = {2004}, language = {en} }