Open AccessX-ray natural linear dichroism of graphitic materials across the carbon K-edge: Correction for perturbing high-order harmonics
Author(s) -
C. Jansing,
H.-Ch. Mertins,
A. Gaupp,
Andréy Sokolov,
Markus Gilbert,
Hud Wahab,
H. Timmers
Publication year - 2016
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/712/1/012031
Subject(s) - harmonics , beamline , pyrolytic carbon , graphene , synchrotron , materials science , highly oriented pyrolytic graphite , optics , linear dichroism , graphite , carbon fibers , silicon , beam (structure) , optoelectronics , circular dichroism , physics , chemistry , nanotechnology , crystallography , organic chemistry , quantum mechanics , voltage , pyrolysis , composite number , composite material
Reflectivity measurements on graphitic materials such as graphene at energies across the carbon K-edge are frustrated by significant intensity loss due to adventitious carbon on beamline mirrors. Such intensity reduction enhances effects due to perturbing high-order harmonics in the beam. These effects distort the actual structure of the reflectance curve. In order to overcome this limitation, a correction technique has been developed and demonstrated first with measurements for highly ordered pyrolytic graphite. The same approach may be applied to other graphitic materials such as graphene and it may be used with other synchrotron beamlines. The fraction of high-order harmonics was determined by passing the incident beam through a 87 nm thin silicon nitride absorber that can be well modeled. Using the corrected measurements the x-ray natural linear dichroism of the sample has been determined