Certification of Standard Reference Material 1976B

2015 ◽  
Vol 30 (3) ◽  
pp. 199-204 ◽  
Author(s):  
David R. Black ◽  
Donald Windover ◽  
Marcus H. Mendenhall ◽  
Albert Henins ◽  
James Filliben ◽  
...  
Keyword(s):  
Reference Material ◽  
Powder Diffraction ◽  
Standard Reference Materials ◽  
Third Generation ◽  
Line Position ◽  
X Ray ◽  
The Third ◽  
Intensity Measurements ◽  
Peak Intensity ◽  
Relative Peak Intensity

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to address specific aspects of the performance of X-ray powder diffraction instruments. This report describes SRM 1976b, the third generation of this powder diffraction SRM. SRM 1976b consists of a sintered alumina disc, approximately 25.6 mm in diameter by 2.2 mm in thickness, intended for use in the calibration of X-ray powder diffraction equipment with respect to line position and intensity as a function of 2θ-angle. The sintered form of the SRM eliminates the effect of sample loading procedures on intensity measurements. Certified data include the lattice parameters and relative peak intensity values from 13 lines in the 2θ region between 20° and 145° using CuKα radiation. A NIST-built diffractometer, incorporating many advanced and unique design features was used to make the certification measurements.

scholarly journals Certification of Standard Reference Material 1879b respirable cristobalite

2018 ◽  
Vol 33 (3) ◽  
pp. 202-208
Author(s):  
D. R. Black ◽  
M. H. Mendenhall ◽  
P. S. Whitfield ◽  
C. M. Brown ◽  
A. Henins ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Occupational Safety ◽  
Internal Standard ◽  
Lattice Parameter ◽  
Standard Reference Materials ◽  
Phase Purity ◽  
X Ray ◽  
The Third ◽  
Safety And Health ◽  
Quantitative Analyses

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to address specific aspects of the performance of X-ray powder diffraction instruments. This report describes SRM 1879b, the third generation of this powder diffraction SRM. SRM 1879b is intended for use in the preparation of calibration standards for the quantitative analyses of cristobalite by X-ray powder diffraction in accordance with National Institute for Occupational Safety and Health (NIOSH) Analytical Method 7500, or equivalent. A unit of SRM 1879b consists of approximately 5 g of cristobalite powder bottled in an argon atmosphere. It is certified with respect to crystalline phase purity, or amorphous phase content, and lattice parameter. Neutron powder diffraction, both time-of-flight and constant wavelength, was used to certify the phase purity using SRM 676a as an internal standard. A NIST-built diffractometer, incorporating many advanced design features was used for certification measurements for lattice parameters.

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.

scholarly journals Crystal structure solution of an elusive polymorph of Dibenzylsquaramide

2013 ◽  
Vol 28 (S2) ◽  
pp. S470-S480 ◽  
Author(s):  
Anna Portell ◽  
Xavier Alcobé ◽  
Latévi M. Lawson Daku ◽  
Radovan Černý ◽  
Rafel Prohens
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structural Features ◽  
Powder Diffraction Data ◽  
Asymmetric Unit ◽  
X Ray ◽  
The Third ◽  
Group Assignment ◽  
Structure Solution

The crystal structure of the third polymorph of dibenzylsquaramide (Portell, A. et al., 2009), (fig. 1) has been determined from laboratory X-ray powder diffraction data by means of direct space methods using the computing program FOX. (Favre-Nicolin and Černý, 2002) The structure resolution has not been straightforward due to several difficulties on the indexing process and in the space group assignment. The asymmetric unit contains two different conformers, which has implied an additional difficulty during the Rietveld (Rietveld, 1969) refinement. All these issues together with particular structural features of disquaramides are discussed.

X-Ray Powder Diffraction For Studying the Mineralogy of fly ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Gregory I. McCarthy
Keyword(s):  
Fly Ash ◽  
Powder Diffraction ◽  
Reference Materials ◽  
Standard Reference Materials ◽  
National Bureau ◽  
Fly Ashes ◽  
X Ray ◽  
High Calcium

ABSTRACTA brief summary of the use of x-ray powder diffraction for studying the mineralogy of fly ash is presented. Mineralogies of low-, intermediate- and high-calcium fly ashes are discussed and illustrated by results from XRD characterization of U.S. National Bureau of Standards fly ash Standard Reference Materials.

Results of X-Ray Powder Diffraction Round Robin Tests with Corundum Plates and Powder Samples

1995 ◽  
Vol 39 ◽  
pp. 571-577
Author(s):  
V. Valvoda ◽  
D. Rafaja ◽  
R. Jenkins
Keyword(s):  
Powder Material ◽  
Powder Diffraction ◽  
Round Robin ◽  
Specimen Preparation ◽  
Round Robin Test ◽  
X Ray ◽  
Intensity Measurements ◽  
Powder Diffractometer ◽  
Powder Samples ◽  
Line Positions

Repetitions of the round robin test on powder diffractometer sensitivity and round robin test of intensity measurements, using two almost identical groups of participants, enabled a comparison to be made of results obtained in different tests. Two forms of corundum test samples were used: (i) sintered plates in tests A8 and A9, and (ii) powder samples in test Bl . A rough comparison of the influence of different methods of specimen preparation from the powder material in different laboratories in test Bl is thus possible with respect to the (almost) uniform sintered plates used in tests A8 and A9. The parameters under investigation were the line positions (and/or inter-planar d-spacing) and intensities of eleven reflections occurring at the 20 angles ranging from 25° to 136° for Cu Kα-radiation

Shadow: A System for X-ray Powder Diffraction Pattern Analysis

1988 ◽  
Vol 32 ◽  
pp. 523-530
Author(s):  
Scott A. Howard
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Pattern Analysis ◽  
Shadow System ◽  
X Ray ◽  
The Third

The Shadow system consists of a set of programs and files, the relation of which is illustrated in Figures 1 and 2. Of the three programs in the system, Shadow and XRDPLT are used routinely. The third, INSCAL, is used in the determination of various parameters characterizing the instrument. Two files, Shadow.DFT and XRDPLT.DFT, contain default values for parameters controlling the reduction and display of data. A third file, WSGDAT, contains the instrument parameters.

Certification of standard reference material 1878b respirable α-quartz

2016 ◽  
Vol 31 (3) ◽  
pp. 211-215 ◽  
Author(s):  
David R. Black ◽  
Marcus H. Mendenhall ◽  
Pamela S. Whitfield ◽  
Donald Windover ◽  
Albert Henins ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Occupational Safety ◽  
Internal Standard ◽  
Lattice Parameter ◽  
Standard Reference Materials ◽  
Quartz Powder ◽  
Phase Purity ◽  
X Ray ◽  
Safety And Health ◽  
Quantitative Analyses

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to address specific aspects of the performance of X-ray powder diffraction instruments. This report describes SRM 1878b, the third generation of this powder diffraction SRM. SRM 1878b is intended for use in the preparation of calibration standards for the quantitative analyses of α-quartz by X-ray powder diffraction in accordance to National Institute for Occupational Safety and Health Analytical Method 7500, or equivalent. A unit of SRM 1878b consists of approximately 5 g of α-quartz powder bottled in an argon atmosphere. It is certified with respect to crystalline phase purity, or amorphous phase content, and lattice parameter. Neutron powder diffraction, both time of flight and constant wavelength, was used to certify the phase purity using SRM 676a as an internal standard. A NIST-built diffractometer, incorporating many advanced design features was used for certification measurements for lattice parameters.

scholarly journals Physical sciences at Diamond: past achievements and future opportunities

2015 ◽  
Vol 373 (2036) ◽  
pp. 20130150 ◽  
Author(s):  
D. F. McMorrow
Keyword(s):  
Light Source ◽  
Third Generation ◽  
Physical Sciences ◽  
Personal View ◽  
X Ray ◽  
The Third ◽  
The Uk

The start of user operation at the Diamond Light Source in January 2007 marks a major milestone for the physical sciences in the UK. The routine delivery to the UK community of ultra-bright X-ray beams from the third-generation source has provided us with capabilities that were available previously only at international sources, and indeed has created some that are unique. Here, a personal view is given of some of the achievements to date, and possible future opportunities outlined.

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