Regensburg 1998 – wissenschaftliches Programm
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O: Oberflächenphysik
O 34: Poster (II)
O 34.24: Poster
Donnerstag, 26. März 1998, 20:00–22:30, Bereich C
New Experimental Technique: X-Ray Absorption Spectroscopy for in situ Studies in the Soft X-Ray Range (250 eV ≤ hν ≤ 1000 eV) under Reaction Conditions — •A. Knop-Gericke, M. Hävecker, and Th. Schedel–Niedrig — Fritz–Haber–Institut der MPG, Faradayweg 4–6, D-14195 Berlin
A novel tank reactor equipped with total electron yield (TEY)
detectors was designed and constructed for in situ X-ray
absorption spectroscopy (XAS) in the soft X-ray range (250 eV ≤
hν ≤ 1000 eV) under elevated pressures (up to 20 mbar) and
sample temperatures (up to 900 K). This allows, for the first
time, XAS studies in the TEY mode at the K-absorption edges of the
low atomic number elements like carbon, nitrogen and oxygen with
high surface sensitivity. Furthermore, the gas phase XAS and the
surface-related XAS of the catalyst can be collected simultaniously
in order to correlate the gas/solid reaction rate with the
electronic structure of the sample surface and near-surface region.
This work presents the experimental technique and the oxygen K- and
copper L2,3 X-ray absorption near-edge structures (XANES) of
Cu(poly) obtained under various gas environments and reaction
temperatures.
(A. Knop–Gericke, M. Hävecker, Th. Neisius and Th.
Schedel–Niedrig, Nucl. Instr. Meth., submitted 10/97)