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Plenarvortrag Mi., 17:00–17:30 M-PV3
Zone-plate based Microspectroscopy with soft x-rays
Rainer Fink 1
1 Physikalische Chemie II, Univ. Erlangen, Egerlandstraße 3, 91058 Erlangen
With the advance in the fabrication of micro zone plates focusing of x-rays down to
about 20 nm has been demonstrated [1]. Taking advantage of the high brilliance of
3 rd generation synchrotron sources, high-resolution spectroscopy can be combined with
high spatial resolution. Scanning-transmission microspectroscopy offers many different
applications with lateral resolutions well below 50 nm routinely in an easy-to use experiment.
The operation of the microscope in either He atmosphere or in vacuum allows
the investigation of thin solid films and liquid films in wet cells. The BMBF funded
PolLux project, which is presently under commissioning at the Swiss Light Source
(SLS, Paul Scherrer Institut, Villigen) will be a microspectroscopy facility which offers
a wide variety of experimental possibilities in the photon energy range from 260 to
1100 eV. PolLux is an interferometrically controlled STXM based on the ALS polymer
STXM design [2]. We make particular use of the high stability of the stored electron
beam at the SLS, which is a prerequisite for high spatial resolution. Steering of the
beam will even allow one to perform XMCD experiments with fast switching of the
helicity or time-resolved experiments (although the instrument is installed at a bending
magnet beamline). Several applications of STXM shall be discussed in this contribution.
Emphasis will be lying on the investigation of so-called soft matter samples,
which were prepared as thin films either by dip- or spin coating. The materials used
range from functionalized π-conjugated molecules, molecular magnets, liquid crystal
films, and block copolymers. The near-edge x-ray absorption fine structure (NEXAFS)
is used to explore the structure-dependent electronic structure of nanostructured selforganized
films, which in some cases form small nanosized crystals. Other examples to
be discussed will be biologically relevant samples (e.g. human hair, insect eyes), which
are sometimes difficult to image in routinely used transmission electron microscopy.
Present STXM highlights concern the investigation of the magnetization dynamics in
magnetic nanostructures using time-resolved NEXAFS. In these systems, STXM is superior
compared to commonly used XPEEM studies [3]. This project is funded by the
BMBF under contract 05 KS4WE1/6.
[1] Weilun Chao, B.D. Harteneck1, J.A. Liddle, E.H. Anderson, and D.T. Attwood,
Nature 435 (2005) 1210
[2] A.L.D. Kilcoyne, T. Tyliszczak et al., J. Synchrotr. Rad. 10(2003) 125
[3] A. Puzic A, B. Van Waeyenberge, K.W. Chou et al., J. Appl. Phys. 97(10) (2005)
10E704