X-Ray Diffraction Profile Analysis of Powdered Samples

1989 ◽  
Vol 4 (2) ◽  
pp. 70-73 ◽  
Author(s):  
G.J. Stanisz ◽  
J.M. Holender ◽  
J. Sołtys

AbstractA quantitative phase analysis often requires advanced numerical studies to determine the appropriate intensity values. In this paper the method of fitting analytical functions to the experimental profile is applied to X-ray powder diffraction patterns obtained with FeK radiation. In the present work, the authors examine some problems connected with numerical studies, especially the function describing the experimental profile. The usefulness of the α2 elimination procedure and the angular dependence FWHM are also examined.

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1841
Author(s):  
Edgar Pio ◽  
Ariosto Medina ◽  
Carola Martínez ◽  
Felipe Manuel Castro Cerda ◽  
Claudio Aguilar

Four titanium alloys (Ti-Ta, Ti-Ta-Sn, Ti-Ta-Mn, and Ti-Nb-Sn) were synthesized by mechanical alloying (MA) in a planetary mill in different times between 2 h and 100 h. The microstructure characterization was made by X-ray diffraction (XRD), in which the Rietveld method was applied to analyze the diffraction patterns. The study demonstrated that after short milling times between 2 h and 30 h, the fraction of hexagonal close-packed (hcp) phase decreases; at the same time, the formation of body-centered cubic (bcc) and face-centered cubic (fcc) Ti phases are promoted. Additionally, after 30 h of MA, the full transformation of hcp-Ti was observed, and the bcc-Ti to fcc-Ti phase transformation took place until 50 h. The results suggest that the addition of Ta and Sn promotes the fcc-Ti phase formation, obtaining 100% of this phase at 50 h onwards, whereas Nb and Mn show the opposite effect.


2008 ◽  
Vol 39 (8) ◽  
pp. 1978-1984 ◽  
Author(s):  
S. Mahadevan ◽  
T. Jayakumar ◽  
B.P.C. Rao ◽  
Anish Kumar ◽  
K.V. Rajkumar ◽  
...  

1990 ◽  
Vol 34 ◽  
pp. 369-376
Author(s):  
G. J. McCarthy ◽  
J. M. Holzer ◽  
W. M. Syvinski ◽  
K. J. Martin ◽  
R. G. Garvey

AbstractProcedures and tools for evaluation of reference x-ray powder patterns in the JCPDSICDD Powder Diffraction File are illustrated by a review of air-stable binary oxides. The reference patterns are evaluated using an available microcomputer version of the NBS*A1DS83 editorial program and PDF patterns retrieved directly from the CD-ROM in the program's input format. The patterns are compared to calculated and experimental diffractograms. The majority of the oxide patterns have been found to be in good agreement with the calculated and observed diffractograms, but are often missing some weak reflections routinely observed with a modern diffractometer. These weak reflections are added to the PDF pattern. For the remainder of the phases, patterns are redetermined.


2014 ◽  
Vol 950 ◽  
pp. 48-52
Author(s):  
De Gui Li ◽  
Ming Qin ◽  
Liu Qing Liang ◽  
Zhao Lu ◽  
Shu Hui Liu ◽  
...  

The Al2M3Y(M=Cu, Ni) compound was synthesized by arc melting under argon atmosphere. The high-quality powder X-ray diffraction data of Al2M3Y have been presented. The refinement of the X-ray diffraction patterns for the Al2M3Y compound show that the Al2M3Y has hexagonal structure, space groupP6/mmm(No.191), with a = b = 5.1618(2) Å, c = 4.1434(1) Å,V= 95.6 Å3,Z= 1,ڑx= 5.7922 g/cm3,F30= 155.5(0.0057, 34), RIR = 2.31 for Al2Cu3Y, and with a = b = 5.0399(1) Å, c = 4.0726(1) Å,V= 89.59 Å3,Z= 1,ڑx= 5.9118 g/cm3,F30= 135.7(0.0072, 30), RIR = 2.54 for Al2Ni3Y.


1989 ◽  
Vol 33 ◽  
pp. 397-402 ◽  
Author(s):  
Shin'ichi Ohya ◽  
Yasuo Yoshioka

When an x-ray diffraction profile Is measured for stress analysis or profile analysis by the use of a linear (straight line) position sensitive proportional counter (PSPC) , a convex-type background line is obtained because of the geometrical problem and the absorption of x-rays. Such phenomenon is remarkable when a wide angular range is set on a linear PSPC and it is, in particular, necessary to correct with a straight background for accurate measurement of diffraction angle or half-value breadth of the broadened diffraction profile.


1994 ◽  
Vol 38 ◽  
pp. 387-395 ◽  
Author(s):  
Walter Kalceff ◽  
Nicholas Armstrong ◽  
James P. Cline

Abstract This paper reviews several procedures for the removal of instrumental contributions from measured x-ray diffraction profiles, including: direct convolution, unconstrained and constrained deconvolution, an iterative technique, and a maximum entropy method (MEM) which we have adapted to x-ray diffraction profile analysis. Decorevolutions using the maximum entropy approach were found to be the most robust with simulated profiles which included Poisson-distributed noise and uncertainties in the instrument profile function (IPF). The MEM procedure is illustrated by application to the analysis for domain size and microstrain carried out on the four calcined α-alumina candidate materials for Standard Reference Material (SRM) 676 (a quantitative analysis standard for I/Ic determinations), along with the certified material. Williamson-Hall plots of these data were problematic with respect to interpretation of the microstrain, indicating that the line profile standard, SRM 660 (LaB6), exhibits a small amount of strain broadening, particularly at high 2θ angle. The domain sizes for all but one of the test materials were much smaller than the crystallite (particle) size; indicating the presence of low angle grain boundaries.


1983 ◽  
Vol 27 ◽  
pp. 307-316
Author(s):  
J. Nissenbaum ◽  
A. Levi ◽  
A. Burger ◽  
M. Schieber ◽  
Z. Burshtein

AbstractWe have explored the merits of using a Hgl2 spectrometer as a detector in x-ray diffraction systems instead of a proportional gas counter, or a scintillation counter. The full width at half maximum energy resolution of the HgI2 spectrometer used was about 1.1 keV for the CuKα line (8.1 keV), and about 1.5 keV for the MoKα line (17.4 keV), The energy resolution was utilised to eliminate x-ray fluorescence background from powder diffraction spectra. We demonstrate the suppression of Fe x-ray fluorescence in diffraction patterns of ErFe03 obtained with a Cu x-ray tube, and of Y x-ray fluorescence in diffraction patterns of Y2O3 obtained with a Mo x-ray tube. The peak height to background ratios were improved by about an order of magnitude in both cases.


1961 ◽  
Vol 7 (5) ◽  
pp. 477-481 ◽  
Author(s):  
Jonathan Parsons ◽  
John R Bartone

Abstract The use of X-ray diffraction to identify crystals from the fluid obtained from a brain tap is illustrated. The procedure for making this type of analysis is described and a very brief description of X-ray diffraction process given. Photographs of the powder diffraction patterns are included, as well as a table giving the interplanar distances and relative intensities corresponding to the pattern for cholesterol.


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