Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 11: Poster: New Instruments and Methods

CPP 11.9: Poster

Montag, 14. März 2011, 17:30–19:30, P2

Contrast enhancement in STXM micrographs based on radiation damage — •Andreas Späth¹, Jörg Raabe², and Rainer H. Fink¹ — ¹Friedrich-Alexander Universität Erlangen-Nürnberg, Physikalische Chemie II and ICMM, Erlangen, Germany — ²Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland

Radiation damage is not avoidable during resonant absorption of highly-energetic intense ionizing radiation like soft x-rays. In order to quantify its effect in x-ray microspectroscopy it is crucial to evaluate material specific critical doses as upper irradiation limit to detect the chemical species of interest and not its decomposition products. In particular in soft matter specimens sample degradation is particularly important [1]. For some materials, however, radiation damage can enhance the contrast in x-ray micrographs as will be demonstrated for microtomed slices of insect eyes (xanthopan morganii predicta). We can demonstrate that radiation energy dependent contrast enhancement is observed due to selective mass loss in anatomically different regions. The studies are completed by dose dependent studies of ultrathin polymer films and polymer bilayers with specific emphasis on the resonant and non-resonant excitations. We will employ these effects to quantify the contrast enhancement in STXM micrographs. In-situ AFM studies at the NanoXAS instrument offers direct correlations with local thickness variations [2]. The work is funded by the BMBF, contract 05K10WEA.

[1] J. Wang et al. J. Electron Spectrosc. Rel. Phenom. 170, 2009, 25

[2] I. Schmid et al. J. Phys. Conf. Ser. 186, 2009, 012015