Research on Influence of Diffractometer Slits on XRD Pattern

X-ray diffraction analysis is a convenient and important route to investigate crystalline materials. With powder materials, calcium carbonate as target, the effects of scatter slit, soller slit and receiving slit of Bruker D8 ADVANCE diffractometer on the diffraction pattern based on information, such as the background intensity, peak height, intensity and full width at half maximum, which provide the evidence for slits selection.

Effect of Slit Width on the Results of Small-Angle X-Ray Diffraction

X-ray diffraction analysis is a convenient and important route to investigate crystalline materials. With mesoporous materials, Al-SBA-15 as target, the effects of scatter slit, soller slit and receiving slit of Bruker D8 ADVANCE diffractometer on the small-angle diffraction pattern based on information, such as the background intensity, peak height, intensity and full width at half maximum, which provide the evidence for slits selection.

The Effect of Soller Slit and Monochromator Used for Background Reduction in Texture Measurements

An X-ray texture goniometer equipped with a vertical Soller slit and a monochromator in the secondary beam in combination with Cu radiation is found to be useful for pole figure measurements on different materials, e.g. Al and Fe, as well as for low incident beam angle measurements on thin coatings. The obtained ODF's are less sensitive to errors in the procedure used for background correction of the pole figures than obtained with the classical setup used for pole figure measurements. The reason for that is the drastically ameliorated Intensity/Background (I/B) ratio by the use of the monochromator. Examples for cold rolled Fe and Al are presented. One of the merits of the new setup is that pole figures of Al, Cu, Ti, Fe can all be measured by using Cu Kα radiation, thus avoiding frequent and time-consuming exchanges of X-ray tubes.

Measurement of the Refraction Correction for Asymmetric Grazing Incidence Xrd From Rough Surfaces and Powders

The refraction effect at small incidence angles was investigated for solid Al2O3 disks of varying surface roughness, and Al2O3 and LaB6 powder layers of varying thickness and roughness using pseudo parallel beam optics. For the disks the peak shift Δ2θ correlated approximately inversely with ζmax, the maximum slope of a sinusoidal model of the surface roughness. For a disk polished with 3θm diamond, Δ2θ exceeded that predicted by the James equation. For the powder layers Δ2θ was very small for the thinnest layers. For thicker, rougher layers Δ2θ was larger and was probably due to displacement error from the 0.4° divergence of the Soller slit used and specular reflection of the diffracted beam from the Soller slit leaves.

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.

An Analysis of the Effect of Different Instrumental Conditions on the Shapes of X-ray Powder Line Profiles

In this investigation we have examined how the full width at half maximum intensity (FWHM) and asymmetry of x-ray powder diffraction line profiles are influenced by the instrumental conditions adopted. Experimental x-ray data has been collected for a matrix of instrumental conditions by systematically varying the divergence slit angle (and the corresponding anti-scatter slit) over the range 0.25° to 1.25°, by using either a 0.05mm or 0.2mm receiving slit, or by removing the diffracted beam Soller slit. The line profile Standard Reference Material, SRM, 660 (LaB6) was used as the powder specimen in that it imparts minimal specimen induced broadening to the diffraction profiles. X-ray data were collected on a conventional, divergent beam, x-ray diffractometer using CuKα radiation. The FWHM of the CuKα1 component can be as low as 0.035°2θ for high resolution conditions, but is normally ∼0.1°2θ at 2θ ≈ 30° for the instrumental conditions adopted in routine diffractometry. Below 2θ = 50°, the divergence slit has a significant effect on the FWHM and is the major cause of the increase in FWHM with decreasing 2θ. Results are presented of the 2θ dependence of FWHM values for each of the instrumental conditions recorded. A general relationship for the 2θ dependence of the FWHM and the asymmetry has been investigated to supersede the inappropriate Cagliotti expression frequently used in x-ray Rietvcld refinement.