Qualitative Analysis of Complicated Mixtures by Profile Fitting X-Ray Diffractometer Patterns

1978 ◽  
pp. 275-288 ◽  
Author(s):  
T. C. Huang ◽  
William Parrish
Keyword(s):  
Qualitative Analysis ◽  
X Ray ◽  
Profile Fitting

Qualitative Analysis of Complicated Mixtures by Profile Fitting X-Ray Diffractometer Patterns

1977 ◽  
Vol 21 ◽  
pp. 275-288 ◽  
Author(s):  
T. C. Huang ◽  
William Parrish
Keyword(s):  
Qualitative Analysis ◽  
Reference Standards ◽  
X Ray ◽  
Match Procedure ◽  
Window Width ◽  
Profile Fitting ◽  
Fitting Method

The analysis of mixtures of phases which produce complicated composite x-ray powder patterns is greatly facilitated by use of our profile fitting method and the technique of applying it is illustrated with a five-compound mixture. Profile fitting gave higher precision in the determination of the reflection angles and Intensities and resolved overlaps in a much shorter time than with other methods. If the reference standards are obtained with the same precision, a smaller error window width can b e used in the search/match procedure.

scholarly journals Hydrothermal Synthesis of Iridium-Substituted NaTaO3 Perovskites

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1537
Author(s):  
David L. Burnett ◽  
Christopher D. Vincent ◽  
Jasmine A. Clayton ◽  
Reza J. Kashtiban ◽  
Richard I. Walton
Keyword(s):  
Significant Proportion ◽  
Edge Length ◽  
Perovskite Oxide ◽  
Hydrogen Yield ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Profile Fitting ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
One Step

Iridium-containing NaTaO3 is produced using a one-step hydrothermal crystallisation from Ta2O5 and IrCl3 in an aqueous solution of 10 M NaOH in 40 vol% H2O2 heated at 240 °C. Although a nominal replacement of 50% of Ta by Ir was attempted, the amount of Ir included in the perovskite oxide was only up to 15 mol%. The materials are formed as crystalline powders comprising cube-shaped crystallites around 100 nm in edge length, as seen by scanning transmission electron microscopy. Energy dispersive X-ray mapping shows an even dispersion of Ir through the crystallites. Profile fitting of powder X-ray diffraction (XRD) shows expanded unit cell volumes (orthorhombic space group Pbnm) compared to the parent NaTaO3, while XANES spectroscopy at the Ir LIII-edge reveals that the highest Ir-content materials contain Ir4+. The inclusion of Ir4+ into the perovskite by replacement of Ta5+ implies the presence of charge-balancing defects and upon heat treatment the iridium is extruded from the perovskite at around 600 C in air, with the presence of metallic iridium seen by in situ powder XRD. The highest Ir-content material was loaded with Pt and examined for photocatalytic evolution of H2 from aqueous methanol. Compared to the parent NaTaO3, the Ir-substituted material shows a more than ten-fold enhancement of hydrogen yield with a significant proportion ascribed to visible light absorption.

Development of Gas Scintillation Proportional Counter

1999 ◽  
Vol 09 (03n04) ◽  
pp. 169-174
Author(s):  
N. Shigeoka ◽  
K. Mutaguchi ◽  
Y. Nakanishi ◽  
Y. Ito ◽  
T. Mukoyama ◽  
...  
Keyword(s):  
Proportional Counter ◽  
Pulse Height ◽  
Acceleration Region ◽  
X Ray ◽  
Gaussian Profile ◽  
Profile Fitting ◽  
Fitting Method

The properties of gas scintillation proportional counter are investigated for Mn K x-ray spectra. The pulse-height spectra are strongly affected by changing of the value of a potential V 2 in the acceleration region and analyzed by the Gaussian profile fitting method.

Total reflection X-ray Fluorescence determination of interfering elements rubidium and uranium by profile fitting

2018 ◽  
Vol 144 ◽  
pp. 87-91 ◽  
Author(s):  
Sangita Dhara ◽  
Ajay Khooha ◽  
Ajit Kumar Singh ◽  
M.K. Tiwari ◽  
N.L. Misra
Keyword(s):  
Total Reflection ◽  
X Ray ◽  
Fluorescence Determination ◽  
Profile Fitting

scholarly journals Crystallization of Cu60Zr20Ti20 bulk metallic glass by high pressure torsion

2019 ◽  
Vol 58 (1) ◽  
pp. 304-312
Author(s):  
Ádám Révész ◽  
András Horváth ◽  
Gábor Ribárik ◽  
Erhard Schafler ◽  
David J. Browne ◽  
...  
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Crystallite Size ◽  
Bulk Metallic Glass ◽  
High Pressure Torsion ◽  
Average Crystallite Size ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Microstructural Parameters ◽  
Profile Fitting

Abstract Bulk metallic glass of Cu60Zr20Ti20 composition has been synthesized by copper mold casting. Slices of the as-cast glass has been subjected to severe plastic deformation by high-pressure torsion for different whole turns. The microstructure and the thermal behavior of the deformed disks have been investigated by X-ray diffraction and differential scanning calorimetry. It was confirmed that the initial compression preceding the high pressure torsion induces crystallized structure, which shows only minor further changes upon the severe plastic shear deformation achieved by twisting the sample. The X-ray line profiles have been evaluated by the Convolutional Whole Profile Fitting algorithm in order to determine the evolution of the microstructural parameters, such as the median and variance of the crystallite size distribution, average crystallite size and dislocation density as a function of the number of revolutions. Hardness measurements by nanoindentation have also been carried out on the as-cast alloys and the deformed disks.

scholarly journals Integration of macromolecular diffraction data

1999 ◽  
Vol 55 (10) ◽  
pp. 1696-1702 ◽  
Author(s):  
A. G. W. Leslie
Keyword(s):  
Diffraction Data ◽  
Standard Error ◽  
Standard Errors ◽  
X Ray ◽  
Poisson Statistics ◽  
Profile Fitting ◽  
X Ray Background

Diffraction intensities can be evaluated by two distinct procedures: summation integration and profile fitting. Equations are derived for evaluating the intensities and their standard errors for both cases, based on Poisson statistics. These equations highlight the importance of the contribution of the X-ray background to the standard error and give an estimate of the improvement which can be achieved by profile fitting. Profile fitting offers additional advantages in allowing estimation of saturated reflections and in dealing with incompletely resolved diffraction spots.

Accuracy in Angle and Intensity Measurements in X-Ray Powder Diffraction

1982 ◽  
Vol 26 ◽  
pp. 1-10 ◽  
Author(s):  
Robert L. Snyder
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Crystal Structure Analysis ◽  
Phase Identification ◽  
X Ray ◽  
New Horizons ◽  
Intensity Measurements ◽  
Profile Fitting ◽  
Computer Automation ◽  
Qualitative Phase

The advent of computer automation and profile fitting techniques in powder diffraction., along with a general solution to the problem of preferred orientation, has opened a series of new horizons for this method. The new levels of accuracy attainable have brought us to the threshold of routine reliable qualitative phase identification, high precision quantitative analysis and the ability to perform crystal structure analysis on some of the most important technological materials. It has been primarily the question of accuracy which has held up these developments until now.

A profile-fitting procedure for analysis of broadened X-ray diffraction peaks. I. Methodology. Erratum

1989 ◽  
Vol 22 (2) ◽  
pp. 184-184 ◽  
Author(s):  
S. Enzo ◽  
G. Fagherazzi ◽  
A. Benedetti ◽  
S. Polizzi
Keyword(s):  
X Ray Diffraction ◽  
Correct Equation ◽  
X Ray ◽  
Fitting Procedure ◽  
Profile Fitting ◽  
Diffraction Peaks

Equation (18) of the paper by Enzo, Fagherazzi, Benedetti & Polizzi [J. Appl. Cryst. (1988). 21, 536–542] is in error. The correct equation is: A(2θ) = exp [−a|(2θ − 2θ 0)/cot 2θ 0|].

Energy Dispersive X-ray Diffractometry

1976 ◽  
Vol 20 ◽  
pp. 171-186 ◽  
Author(s):  
Michael Mantier ◽  
William Parrish
Keyword(s):  
Diffraction Peak ◽  
Computer Method ◽  
Energy Dispersive ◽  
Resolution Function ◽  
Detector Resolution ◽  
X Ray ◽  
Profile Fitting

This paper describes the principles, methods, instrumentation and results of EDXKD and a computer method of profile fitting to obtain corrected intensities and peak energies from isolated and overlapping reflections. The profile, P, of a diffraction peak is a convolution of the incident X-ray spectrum, X, the geometrical aberrations, T, the contribution from the specimen, S, and the detector resolution function, D.

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