New Tools for Grazing Incidence Diffraction Measurements: Comparison of Different Primary and Secondary Beam Conditioners

Grazing incidence diffraction (GID) is a powerful tool for the structural characterization of thin films. Unlike traditional Bragg-Brentano geometry (divergent X-ray beam, focusing geometry), GID experiments are enhanced by a parallel beam of high intensity. Classical conditioning of the X-ray beam is done by using small slits on the primary beam side and a long Soller slit in combination with a flat crystal (e.g. graphite, lithium fluoride or germanium) or an energy dispersive detector on the secondary beam side. However, new alternatives for beam conditioners are becoming available which promise increased performance. X-ray beam optics using either planar or graded parabolically curved multilayer mirrors of high reflectivity have been constructed for the primary beam side as well as for the secondary beam side.

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Application of a single-reflection collimating multilayer optic for X-ray diffraction experiments employing parallel-beam geometry

Journal of Applied Crystallography ◽

10.1107/s0021889807050005 ◽

2008 ◽

Vol 41 (1) ◽

pp. 124-133 ◽

Cited By ~ 24

Author(s):

M. Wohlschlögel ◽

T. U. Schülli ◽

B. Lantz ◽

U. Welzel

Keyword(s):

Incident Beam ◽

Grazing Incidence ◽

Photon Flux ◽

Data Sets ◽

Parallel Beam ◽

X Ray ◽

Beam Focusing ◽

Beam Geometry ◽

Parallel Beam Geometry ◽

Diffraction Patterns

Instrumental aberrations of a parallel-beam diffractometer equipped with a rotating anode X-ray source, a single-reflection collimating multilayer optic and a parallel-plate collimator in front of the detector have been investigated on the basis of standard measurements (i.e.employing stress- and texture-free isotropic powder specimens exhibiting small or negligible structural diffraction line broadening). It has been shown that a defocusing correction, which is a major instrumental aberration for diffraction patterns collected with divergent-beam (focusing) geometries, is unnecessary for this diffractometer. The performance of the diffractometer equipped with the single-reflection collimating multilayer optic (single-reflection mirror) is compared with the performance of the diffractometer equipped with a Kirkpatrick–Baez optic (cross-coupled Göbel mirror) on the basis of experimental standard measurements and ray-tracing calculations. The results indicate that the use of the single-reflection mirror provides a significant gain in photon flux and brilliance. A high photon flux, high brilliance and minimal divergence of the incident beam make the setup based on the single-reflection mirror particularly suitable for grazing-incidence diffraction, and thus for the investigation of very thin films (yielding low diffracted intensities) and of stress and texture (requiring the acquisition of large measured data sets, corresponding to the variation of the orientation of the diffraction vector with respect to the specimen frame of reference). A comparative discussion of primary optics which can be used to realise parallel-beam geometry shows the range of possible applications of parallel-beam diffractometers and indicates the virtues and disadvantages of the different optics.

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Application of Grazing Incidence X-Ray Diffraction to Polymer Blends

Advances in X-ray Analysis ◽

10.1154/s037603080001898x ◽

1992 ◽

Vol 36 ◽

pp. 373-377

Author(s):

Mary F. Garbauskas ◽

Donald G. LeGrand ◽

Raymond P. Goehner

Keyword(s):

Polymer Blends ◽

Grazing Incidence ◽

Degree Of Crystallinity ◽

Beam Optics ◽

X Ray Diffraction ◽

Polybutylene Terephthalate ◽

Parallel Beam ◽

X Ray ◽

Injection Molded

AbstractThe physical properties of polymer blends consisting of one or more crystallizable components are affected by the microstructure of these materials. In particular, the degree of crystallinity can be influenced by processing parameters, and the crystallinity, as well as the phase distribution, may vary as a function of depth through an injection molded part. Conventional x-ray diffraction techniques can provide information regarding both phase composition and degree of crystallinity, but, because of the relative transparency of these materials to wavelengths generally available in the laboratory, these techniques provide information representative of only the bulk. By employing parallel beam optics at varying grazing incidence angles, the x-ray sampling depth can be varied without loss of resolution, This technique can be used to vary the effective analysis depth from the top several hundred angstroms for low grazing incidence to centimeters for transmission diffraction patterns, Grazing incidence techniques have found initial application in the characterization of thin metallic and ceramic films. This paper demonstrates the feasibility of using parallel beam optics to depth profile low atomic number materials. The specific application of this technique to the characterization of injection molded polymers, including a blend of bisphenol-A polycarbonate (PC) and polybutylene terephthalate (PBT), will be presented.

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Characterization of lateral semiconductor nanostructures by means of x-ray grazing-incidence diffraction

Applied Physics Letters ◽

10.1063/1.118473 ◽

1997 ◽

Vol 70 (8) ◽

pp. 1031-1033 ◽

Cited By ~ 7

Author(s):

K. Paschke ◽

T. Geue ◽

T. A. Barberka ◽

A. Bolm ◽

U. Pietsch ◽

...

Keyword(s):

Grazing Incidence ◽

Semiconductor Nanostructures ◽

X Ray ◽

Grazing Incidence Diffraction

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Grazing Incidence X-Ray Characterization of Materials

Advances in X-ray Analysis ◽

10.1154/s0376030800018772 ◽

1992 ◽

Vol 36 ◽

pp. 171-184 ◽

Cited By ~ 9

Author(s):

D.K. Bowen ◽

M. Wormington

Keyword(s):

Grazing Incidence ◽

Experimental Techniques ◽

X Rays ◽

Near Surface ◽

X Ray ◽

Grazing Incidence Diffraction ◽

Characterization Of Materials ◽

Grazing Angles

AbstractA review of the methods of characterization of materials using X-rays incident at grazing angles is presented. The rationale of all such methods is the need to obtain information from near-surface regions. The methods include grazing incidence diffraction, reflectivity, diffuse scatter and fluorescence. The experimental techniques are outlined, and the information obtainable and the methods of interpretation are discussed.

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