Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 34: POSTERS Polymerphysics
CPP 34.15: Poster
Donnerstag, 28. Februar 2008, 17:00–19:30, Poster A
Light-Induced Surface Relief Gratings on Novel Low-Molecular-Weight Organic Glasses Containing Azobenzene Side Groups — •Hubert Audorff1, Lothar Kador1, Roland Walker2, and Hans-Werner Schmidt2 — 1Institute of Physics and BIMF, University of Bayreuth, 95440 Bayreuth — 2Macromolecular Chemistry I and BIMF, University of Bayreuth, 95440 Bayreuth
A number of novel low-molecular-weight glass formers with azobenzene moieties has been synthesized to examine the formation of surface relief gratings (SRGs). In addition to birefringent volume gratings, SRGs with heights up to 650 nm were formed in holographic experiments. The amplitudes of the latter were calculated from the diffraction efficiencies and independently measured by atomic-force microscopy. The temporal evolution of the diffraction efficiencies of both types of gratings was monitored. The gradient force model is capable of explaining all the experimental results. The differences between the gratings generated with different writing polarizations can be ascribed to the varying strengths of the gradient force. The influence of the molecular end groups on the SRG formation was investigated. Temperature-dependent measurements allow the determination of the glass transition temperature. At elevated temperatures, the SRG formation rate drops due to increased fluidity of the material.