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Characterization of HAPG mosaic crystals using synchrotron radiation
Author(s) -
Gerlach Martin,
Anklamm Lars,
Antonov Alexander,
Grigorieva Inna,
Holfelder Ina,
Kanngießer Birgit,
Legall Herbert,
Malzer Wolfgang,
Schlesiger Christopher,
Beckhoff Burkhard
Publication year - 2015
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s160057671501287x
Subject(s) - mosaicity , materials science , pyrolytic carbon , optics , diffraction , synchrotron radiation , highly oriented pyrolytic graphite , crystal (programming language) , synchrotron , x ray crystallography , graphite , optoelectronics , chemistry , physics , composite material , organic chemistry , pyrolysis , computer science , programming language
Highly annealed pyrolytic graphite (HAPG) is an advanced type of pyrolytic graphite that, as a mosaic crystal, combines high integral reflectivity with a very low mosaicity of typically less than 0.1°. When used as dispersive X‐ray optics, a high resolving power has been observed, rendering HAPG very suitable for applications in high‐resolution X‐ray spectroscopy, which conventionally relies on ideal crystals. For the design and modelling of HAPG crystals in applications requiring high spectral resolution, the diffraction properties must be known very accurately. To close this gap, a comprehensive characterization of HAPG crystals was performed that allows for modelling of the diffraction properties in different diffraction orders over a broad spectral range. The crystal properties under investigation are the mosaic spread, the peak reflectivity and the intrinsic reflection width. The investigations were carried out for different thickness crystal films, which were mounted adhesively on a substrate. It is shown that the diffraction properties are strongly correlated to the grade of adhesion, which depends crucially on the substrate material and its surface properties. The investigations were performed using monochromated tunable synchrotron radiation of high spectral purity with a high‐precision experimental setup and calibrated detection devices at the electron storage ring BESSY II.