Dresden 2009 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 26: Poster II

DS 26.41: Poster

Mittwoch, 25. März 2009, 09:30–12:30, P5

Phase-contrast imaging in soft x-ray scanning transmission microspectroscopy — •Stephan Wenzel¹, Jörg Raabe², George Tzvetkov¹, Andreas Späth¹, and Rainer H. Fink¹ — ¹Physikal. Chemie 2, Universität Erlangen, Egerlandstr.3, 91058 Erlangen — ²Paul Scherrer Institut, SLS, Villigen, Switzerland

Scanning transmission soft x-ray microspectroscopy (STXM) has proven excellent spatial resolution (down to 20 nm) in combination with spectroscopic information to investigate ultrathin samples. The superior information relies on photon-energy specific absorption which offers high contrast in the obtained images. However, in some cases - often in soft condensed materials (e.g. mixtures of polymers) - local absorption does not exhibit sufficient contrast. It has been demonstrated in hard x-ray microscopy that phase contrast imaging enhances egdes although absorption may be small and negligible. In the soft x-ray regime, phase contrast usually plays a minor role, however, in distinct cases it may give additional information to improve image contrast. In the present PolLux-STXM (installed at the Paul Scherrer Institut, Villigen, Switzerland), we have implemented a 2D detection system (fast read-out CCD), which monitors the angular differences of the transmitted x-rays for each sample spot. Thus, vertical and horizontal phase contrast images can be generated. We will show first examples from various samples to demonstrate the advantages in phase contrast imaging in STXM. The work is funded by the BMBF under contract 05 KS1WE7.