Regensburg 2016 – wissenschaftliches Programm
O 45.11: Poster
Dienstag, 8. März 2016, 18:15–20:30, Poster E
Higher Order Corrected Spectroscopy at the Carbon K Edge — •Christine Jansing1, Hans-Christoph Mertins1, Andreas Gaupp1,2, Andrey Sokolov2, Markus Gilbert1, Andreas Schümmer1, Hud Wahab3, Heiko Timmers3, and Suk-Ho Choi4 — 1Münster University of Applied Sciences, Stegerwaldstr. 39, D-48565 Steinfurt — 2HZB, Albert Einstein Str. 15, D-12489 Berlin — 3University of New South Wales, Canberra, ACT 2600, Australia — 4Kyung Hee University, Yongin 446-701, Korea
We present the experimental determination of disturbing higher order synchrotron radiation across the carbon K edge at a soft x-ray beamline and a procedure to correct spectra of carbonaceous materials like highly oriented pyrolytic graphite (HOPG) or graphene. Measurements in the soft x-ray regime suffer from an enormous loss of photon flux at the C K edge, caused by carbon contamination of the beamlines optical elements. The unavoidable contaminations result from residual organic molecules in the beamline getting cracked by synchrotron radiation and absorbed as adventious carbon on mirrors. In particular first order radiation is absorbed so that incident light has large contributions from higher order wavelengths. We determined the amount of higher order light of up to 60% in the π*-resonance of carbon exploiting a second monochromator and alternatively using a simple filter. We show that both methods reveal a reliable set of data to correct on higher order distortion of our experimental reflection and absorption spectra. This correction procedure can be applied to any carbonaceous material's spectra.