scholarly journals Defocusing in the Reflexion Technique for the Determination of Preferred Orientation Using EDXRD

1982 ◽  
Vol 4 (4) ◽  
pp. 201-210
Author(s):  
J. Kivilä ◽  
E. Laine

The defocusing effect in the reflexion technique for the determination of the preferred orientation using energy-dispersive x-ray diffraction (EDXRD) method is studied experimentally. The measurements show that the defocusing effect is dependent on the Bragg angle, the receiving slit width, the reflexion hkl and the metallurgical condition of the specimen. The defocusing correction or at least the optimizing of the measuring geometry is found to be necessary in quantitative texture measurements.

1976 ◽  
Vol 2 (2) ◽  
pp. 95-111 ◽  
Author(s):  
L. Gerward ◽  
S. Lehn ◽  
G. Christiansen

The use of energy-dispersive X-ray diffraction for quantitative determination of preferred orientations in polycrystalline specimens is analysed. The method is applied to determinations of rolling texture and fibre texture. The adaptability of the method to in situ studies is demonstrated by observations of texture changes simultaneous with the deformation of a specimen in a tension test.


1977 ◽  
Vol 2 (4) ◽  
pp. 243-251 ◽  
Author(s):  
E. Laine ◽  
J. Kivilä ◽  
I. Lähteenmäki

The influence of preferred orientation on integrated x-ray intensities in powder specimen using energy-dispersive diffraction method is investigated. The theory used is based upon examination of the polar axis density distribution. The measurements were carried out using the Schulz technique added with defocusing correction. Experimental results are given for three aluminium powder specimens.


2006 ◽  
Vol 524-525 ◽  
pp. 743-748 ◽  
Author(s):  
Alexander M. Korsunsky ◽  
Shu Yan Zhang ◽  
Daniele Dini ◽  
Willem J.J. Vorster ◽  
Jian Liu

Diffraction of penetrating radiation such as neutrons or high energy X-rays provides a powerful non-destructive method for the evaluation of residual stresses in engineering components. In particular, strain scanning using synchrotron energy-dispersive X-ray diffraction has been shown to offer a fast and highly spatially resolving measurement technique. Synchrotron beamlines provide best available instruments in terms of flux and low beam divergence, and hence spatial and measurement resolution and data collection rate. However, despite the rapidly growing number of facilities becoming available in Europe and across the world, access to synchrotron beamlines for routine industrial and research use remains regulated, comparatively slow and expensive. A laboratory high energy X-ray diffractometer for bulk residual strain evaluation (HEXameter) has been developed and built at Oxford University. It uses a twin-detector setup first proposed by one of the authors in the energy dispersive X-ray diffraction mode and allows simultaneous determination of macroscopic and microscopic strains in two mutually orthogonal directions that lie approximately within the plane normal to the incident beam. A careful procedure for detector response calibration is used in order to facilitate accurate determination of lattice parameters by pattern refinement. The results of HEXameter measurements are compared with synchrotron X-ray data for several samples e.g. made from a titanium alloy and a particulate composite with an aluminium alloy matrix. Experimental results are found to be consistent with synchrotron measurements and strain resolution close to 2×10-4 is routinely achieved by the new instrument.


1999 ◽  
Vol 563 ◽  
Author(s):  
Delrose Winter ◽  
Paul R. Besser

AbstractX-Ray diffraction (XRD) provides an excellent tool for the measurement of both stress and texture (preferred orientation) on fabricated damascene interconnect structures. Since x-ray diffraction provides a direct measurement of lattice spacings, film strain can be measured directly. Also, since the intensity of diffracted x-rays is proportional to the density of lattice planes oriented in diffracting condition with respect to the incident beam, both the direction and extent of preferred orientation can be accurately measured. Special techniques and considerations are necessary when examining damascene interconnect structures with XRD which are not necessary with blanket films. These techniques are discussed and described in order to aid in obtaining meaningful XRD data and a correct interpretation of the results.


2014 ◽  
Vol 47 (5) ◽  
pp. 1708-1715 ◽  
Author(s):  
G. M. Hansford ◽  
S. M. R. Turner ◽  
D. Staab ◽  
D. Vernon

A novel method to separate diffraction and fluorescence peaks in energy-dispersive X-ray diffraction (EDXRD) is described. By tuning the excitation energy of an X-ray tube source to just below an elemental absorption edge, the corresponding fluorescence peaks of that element are completely suppressed in the resulting spectrum. SinceBremsstrahlungphotons are present in the source spectrum up to the excitation energy, any diffraction peaks that lie at similar energies to the suppressed fluorescence peaks are uncovered. This technique is an alternative to the more usual method in EDXRD of altering the scattering angle in order to shift the energies of the diffraction peaks. However, in the back-reflection EDXRD technique [Hansford (2011).J. Appl. Cryst.44, 514–525] changing the scattering angle would lose the unique property of insensitivity to sample morphology and is therefore an unattractive option. The use of fluorescence suppression to reveal diffraction peaks is demonstrated experimentally by suppressing the Ca Kfluorescence peaks in the back-reflection EDXRD spectra of several limestones and dolomites. Three substantial benefits are derived: uncovering of diffraction peak(s) that are otherwise obscured by fluorescence; suppression of the Ca Kescape peaks; and an increase in the signal-to-background ratio. The improvement in the quality of the EDXRD spectrum allows the identification of a secondary mineral in the samples, where present. The results for a pressed-powder pellet of the geological standard JDo-1 (dolomite) show the presence of crystallite preferred orientation in this prepared sample. Preferred orientation is absent in several unprepared limestone and dolomite rock specimens, illustrating an advantage of the observation of rocks in their natural state enabled by back-reflection EDXRD.


1964 ◽  
Vol 19 (12) ◽  
pp. 1363-1376 ◽  
Author(s):  
W. Witt

A technique for the absolute determination of lattice parameters by electron diffraction is described and extensively investigated. The accuracy of the measurement of the BRAGG angle ϑ is tested with DEBYE-SCHERRER diffraction patterns. An improved technique of high-voltage measurement is used in order to obtain very accurate values of the electron wavelength λ. The discussion shows that systematic errors of Δϑ/ϑ = ± 2,5 · 10-5 and Δλ/λ = ± 1,3 ·10-5 result. Thus an accuracy of Δα/α= ± 3 · 10-5 for the lattic constant a can be claimed. This precision is comparable with that of absolute X-ray methods.The reported technique is used for absolute measurements with TlCl crystals prepared by vacuum evaporation, having lateral dimensions of about 1000 A. The lattice constant derived from (100) -, (200) - and (310) -interplanar spacings is in full agreement with the value obtained by X-ray diffraction. The remaining interplanar spacings which can be evaluated are impaired by lattice distortions and thus yield anomalous values for the lattice constant.


1973 ◽  
Vol 17 ◽  
pp. 124-138 ◽  
Author(s):  
A. P. Voskamp

SummaryA time saving method has been applied for the determination of retained austenite.The method involved is based on the approach of energy dispersive X-ray diffraction analysis. With this approach, polychromatic radiation from the X-ray tube is used and diffraction maxima will occur at a fixed angle 2θ in as many wavelengths or energies as “d“ values are present.Giessen and Gordon published the first application of this method to powder diffraction analysis in 1968 for the identification of crystal structures. As the determination of retained austenite is a quantitative type of analysis, based upon identification of the crystal structure, the new approach should also be applicable in principle.With almost 100 samples of unknown austenite content, experiments have been carried out both with the conventional and the energy dispersive X-ray diffraction technique. The results obtained are closely comparable and the retained austenite values together with the errors are shown.For these measurements, experiments have been carried out with the energy dispersive technique to determine the relation between the known concentration of retained austenite in a number of standards and the intensity correction factors (R). The results obtained from these experiments have shown good reproducibility of the intensity correction factors.Using this technique, a five-fold reduction in analysis time is possible over the conventional technique with no reduction in accuracy.


1980 ◽  
Vol 4 (2) ◽  
pp. 63-71 ◽  
Author(s):  
J. Kivilä ◽  
E. Laine ◽  
S. Parviainen

It is shown that energy-dispersive x-ray diffraction (EDXRD) method can be used for correction of integrated intensities for preferred orientation in hexagonal close-packed powders. The theory is based upon examination of the polar axis density distribution and upon the use of hexagonal harmonics in its representation. The reflexion method by Schulz added with defocusing correction was used. Measurements were carried out on three zinc samples with different degrees of orientation, the largest correction being 54 percent.


Sign in / Sign up

Export Citation Format

Share Document