Relative electron inelastic mean free paths for diamond and graphite at 8 keV and intrinsic contributions to the energy-loss

DOI: 10.1016/j.elspec.2009.03.022

Authors: C. Kunz (University of Hamburg) , B. C. C. Cowie (Australian Synchrotron) , W. Drube (Deutsches Elektronen Synchrotron, DESY) , T.-l. Lee (Diamond Light Source) , S. Thiess (Deutsches Elektronen Synchrotron, DESY) , C. Wild (Fraunhofer-Inst. f. Angew. Festkörperphysik, IAF) , J. Zegenhagen (ESRF)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Electron Spectroscopy And Related Phenomena , VOL 173 (1) , PAGES 29-39

State: Published (Approved)
Published: January 2009

Abstract: We used hard X-ray photoelectron spectroscopy (HAXPES) with 8 keV X-rays to investigate the Is emission of carbon. We recorded spectra extending from the peak of the C 1s electrons ("elastic" line) to electrons with Lip to 110 eV energy-loss. Using two samples side by side, we Could compare the inelastic mean free paths (IMFPs) of the electrons of almost 8 keV in diamond and graphite and find them to be practically identical despite about 50% difference in densities. Published extrapolations of their IMFP calculations at lower energies are in good agreement with this result. We show that information from the almost structureless region of overlapping multiple extrinsic energy-losses can be used to quantify the fraction of photoelectrons experiencing intrinsic energy-losses (those due to the sudden creation of the hole). We find that this fraction is 58% of the primary excited C 1s electrons for diamond and is practically the same for graphite. This is at first sight an unexpected result since hole-screening should differ in a semimetal from that in an insulator The observation can be accounted for by dynamic screening in contrast to static screening. (C) 2009 Elsevier B.V. All rights reserved.

Journal Keywords: Hard X-ray photoemission; Synchrotron radiation; Electron attenuation lengths; Diamond; Graphite

Subject Areas: Physics


Instruments: NONE-No attached Diamond beamline

Other Facilities: ESRF

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