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Industrial Group of the BCA
July 1999 - techniquesStandards for Diffraction.Many diffraction users (including myself) are not fully aware of all the standards available to help them in their work. It is the aim of the Industrial Group to put together a list of all the available standards and some hints and tips on their use. In fact it is really two lists as we can consider physical standards or Standard Reference Materials (SRM's) as one list an d Standard Operating Procedures (SOP's) as a separate list. This article is a starting point for these lists, it is not exhaustive and I rely on you to let me know of any that are not included. The lists will be stored and updated on our Web site with links to the various suppliers hopefully into a growing and useful resource. The lists are included as a flyer with this Newsletter. SRMs are costly and some require preparation. An article by Steve Norval in an earlier Newsletter (August 1997) gave details of the preparation of LaB6 and Mica standards. The Round Robin intensity tests use NIST SRM1976 alumina plate and several people have asked how to prepare it to fit into commercial specimen holders. Well the ceramic material can be worked with the same tools used for cutting and shaping your bathroom tiles (it will even cut easily when scored with a glasscutter). The shaped plate is then simply glued from the back with epoxy resin into a hol der using a glass plate as a flat reference surface. For front fill holders place the cut standard on the glass plate with 5 blobs of resin on the back. Carefully place the holder on top and squeeze until it beds on the glass plate.(fig. 1) Figure 1.
If you do not have the confidence to do the work yourself then the Gem Dugout, 1652 Princeton Drive, State College Pennsylvania PA16803 USA Tel: 814 238 4069 e-mai l [email protected] will do it for you (simply send them a holder and a standard plate). Gem Dugout also supply zero background sunstrates from both silicon and quartz crystals. I was unable to finalise details of a UK company who will mount the standard in time for this article but details will be placed on the web as soon as they are available. Standards for low angle calibration are somewhat sparse. The Federal Institute for Materials Research and Testing (BAM) in Germany have a fine grained a cordierite standard in preparation and the mica standard described by Steve is often used. The silver behanate mentioned in Steve's article is still not available from NIST but the Gem Dugout now has a supply. It costs $100 FOR 4 grams has a d001=58.37A. It provides a means to calibrate the angle range 1.5 - 20 degrees 2 theta for CuKA (see above for address).For details of its use see: Blanton, T. N. et al. (1995) JCPDS-ICDD round robin study of silver behanate. A possible low-angle X-ray diffraction calibration standard, Powder Diffraction, v10, 91-95. The SOPs list all come from The American Society for Testing and Materials (ASTM) http://www.astm.org/. I don't know of any recent British or European SOP's for diffraction. However, I do remember one for the determination of amorphous content in cement that involved cutting out and weighing the amorphous hump from a diffraction trace!< /p> I hope you find these lists useful and that you will help to keep them up to date by informing me of any errors or omissions. Dave Taylor E-mail: [email protected] SOP List Standard Operating Procedures relating to diffraction and crystallography available from The American Society for Testing and Materials (ASTM) http://www.astm.org/. These methods can all be purchased direct from this web site. I welcome any comments from users of these methods and details of any other known SOPs and SRMs. E915-96 Standard Test Method for Verifying the Alignment of X-Ray Diffraction Instrumentation for Residual Stress Measurement E1426-98 Standard Test Method for Determining the Effective Elastic Parameter for X-Ray Diffraction Measur ements of Residual Stress D5187-91 Standard Test Method for Determination of Crystallite Size (Lc) of Calcined Petroleum Coke by X-Ray Diffraction D4926-89(1994)e1 Standard Test Method for Gamma Alumina Content in Catalysts Containing Silica and Alumina by X-Ray Powder Diffraction D934-80(1994)e1 Standard Practices for Identification of Crystalline Compounds in Water-Formed Deposits By X-Ray Diffraction D5758-95 Standard Test Method for Determination of Relative Crystallinity of Zeolite ZSM-5 by X-Ray Diffraction D5357-98 Standard Test Method for Determination of Relative Crystallinity of Zeolite Sodium by X-Ray Diffraction D3906-97 Standard Test Method for Relative Zeolite Diffraction Intensities D3720-90(1994)e1 Standard Test Method for Ratio of Anatase to Rutile in Titanium Dioxide Pigments by X-ray Diffraction C1365-98 Standard Test Method for Determination of the Proportion of Phases in Portland Cement and Portland-Cement Clinker Using X-Ray Powder Diffraction Analysis D5380-93(1998) Standard Test Method for Identification of Crystalline Pigments and Extenders in Paint by X-Ray Diffraction Analysis E975-95 Standard Practice for X-Ray Determination of Retained Austenite in S teel with Near Random Crystallographic Orientation F847-94(1999) Standard Test Methods for Measuring Crystallographic Orientation of Flats on Single Crystal Silicon Wafers by X-Ray Techniques F26-87a(1999) Standard Test Methods for Determining the Orientation of a Semiconductive Single Crystal E82-91 Standard Test Method for Determining the Orientation of a Metal Crystal E81- 96 Standard Test Method for Preparing Quantitative Pole Figures D933-84(1994)e1 Standard Practice for Reporting Results of Examination and Analysis of Water-Formed Deposits D3942-97 Standard Test Method for Determination of the Unit Cell Dimension of a Faujasite-Type Zeolite � Dave Taylor SRM ListSt andard Reference Materials supplied by NIST National Institute for Standards and Testing (USA) Check the NIST web site Standard Table for the latest information on standard availability price and certificates. They can all be purchased from a UK agent in pounds sterling - contact Bureau of Analysed Standards on 01642 300500. Other UK suppliers include: MBH Tel 0181441 2024 and Laboratory of the Government Chemist
SRM Type Application Lattice Parameters(in nm) Unit Size(in g)
640c Silicon Powder 2Theta/d-Spacing Line Position In Prep
656 Silicon Nitride Quantitative Analysis Alpha -(0.7752630 / 0.5619372)
Beta -(0.7602293 / 0.2906827)
660a LaB6 Line Profile In Pr
ep In Prep
674a Intensity Quantitative Analysis(Set of 5)
Al2O3 (corundum) (0.4759397 /1.299237) 10
CeO2 (fluorite) (0.5411102) 10
Cr2O3 (corundum) (0.4959610 / 1.358747) 10
TiO2 (rutile) (0.4593939 / 0.2958862) 10
ZnO (wur
tzite) (0.3249074 / 0.5206535) 10
675 Mica Line Position - Low 2Theta 0.998104 7.5
676 Alumina(corundum) Quantitative Analysis 0.475919 / 1.299183 20
1878a Respirable Quartz Quantitative Analysis In Prep
1879a " Cristobalite Quantitative Analysis In Prep In Prep
1976 Alumina Plate, Instrument Response 0.4758846 /
1.299306 4.5 x 4.5 cm x 0.16cm
1990 Ruby Sphere Quantitative Analysis In Prep
2910 Calcium
Hydroxyapatite Quantitative Analysis (a-0.942253) (c-0.688501) 5
Values in parentheses are not certified but are provided as reference values or are given for information only. SRMs 656, 676, 674a, 1878a and 1879c consist of high phase purity materials for use in the quantitative analysis of samp les by the internal standard method. SRM 656, consist of 2 silicon nitride powders, one high in a, the other high in b. SRMs 640c, 660a, 675, and 1976 consist of materials with select crystallographic and microstructure properties used in the evaluation of diffraction equipment for the following variables; 1) d-spacing or line position, 2) line or instrument intensity, and 3) instrumental or sample contributions to the shape of reflection profiles. SRM 19 76, a sintered alumina plate, is also certified with respect to lattice parameters as well as 12 relative intensity values from 25° to 145° 2 theta (Cu Ka ). SRM 1990 will be certified for lattice parameter. SRM 2910 is a high purity synthetic calcium hydroxyapatite for which line profile, relative intensity, lattice parameter, and crystallographically disordered material fraction reference data have been provided. OTHER SOURCES of Standard Refer ence MaterialsThe Gem Dugout 1652 Princeton Drive, State College Pennsylvania PA16803 USA Tel/Fax: 814 238 4069 e-mail [email protected]
Indian Reference Materials NPL National Physical Laboratory, Dr K S Krishnan Rd, New Delhi 110012 INDIA E-mail [email protected] BND1501 Silicon Powder for XRD d-spacing of first 5 reflections 5g 6000(Rs) prepayment by bank draft Director, National Physical Laboratory, New Dehli hkl d Sigma(d) 111 3.1340 0.0073 220 1.9194 0.0029 311 1.6371 0.0022 400 1.3576 0.0014 331 1.2459 0.0011 Dave Taylor |
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