National Institute of Standards & Technology

Certificate of Analysis
Standard Reference Material 1979
Powder Diffraction Line Profile Standard for Crystallite Size Analysis(Nano-Crystalline Zinc Oxide Powder)This Standard Reference Material (SRM) is intended for use in the analysis of crystallite size through the degree of
profile broadening in a powder diffraction experiment. A unit of SRM 1979 consists of two samples of zinc oxide
powder, the first with a median crystallite size of approximately 15 nm and a second with a median of approximately
60 nm. These samples are referred to hereafter as the “15 nm crystallites” and “60 nm crystallites” respectively. Eachsample contains approximately 3 g of powder bottled in an argon atmosphere.
Material Description: The SRM material was prepared from the decomposition of zinc oxalate through procedures
based on those reported by Langford, et al. [1]. The specific annealing procedures were tailored to yield theaforementioned two crystallite size ranges. The diffraction profiles of the powders display the effects of stacking
faults, as observed by Langford, et al., that follow the hexagonal model developed by Warren [2]. The two powders
have median particle sizes, measured via laser scattering, of 2.8 µm and 7.7 µm for the 15 nm and 60 nm crystallites
respectively; as such, both powders consist of aggregated crystallites. An analysis of diffraction line shape and lattice
parameters determined from X-ray powder diffraction data established that the two SRM materials were homogeneouswith respect to diffraction properties.
Certified Values: A NIST certified value is a value for which NIST has the highest confidence in its accuracy in thatall known or suspected sources of bias have been investigated or taken into account. The measurands are the certified
mean column lengths as determined by a Fourier analysis of 22 diffraction lines and the lattice parameters as
determined from Pawley analyses. Metrological traceability is to the International System of Units (SI) unit for length(expressed as nanometers). Certified values and uncertainties are provided in Tables 1 through 4, and were calculated
according to the method described in the ISO/JCGM Guide [3].
Information Values: The information values for the microstructural parameters obtained from refinements of the data
are presented in Table 5. The information data on the particle size distribution, as determined by laser scattering, aregiven in Figures 1 and 2. An information value is considered to be a value that will be of interest and use to the SRM
user, but insufficient information is available to adequately assess the uncertainty associated with the value, or it is avalue derived from a limited number of analyses. Information values cannot be used to establish metrologicaltraceability.
Expiration of Certification: The certification of SRM 1979 is valid indefinitely, within the measurement uncertainty
specified, provided the SRM is handled and stored in accordance with instructions given in this certificate (see“Instructions for Storage and Use”). Periodic recertification of this SRM is not required. The certification is nullified
if the SRM is damaged, contaminated, or otherwise modified. This material degrades with exposure to humidity. If
excessive exposure is suspected, discontinue use.
Maintenance of SRM Certification: NIST will monitor this SRM over the period of its certification. If substantive
changes occur that affect the certification, NIST will notify the purchaser. Registration (see attached sheet or register
online) will facilitate notification.
Material preparation, measurements, and data analysis leading to the certification of this SRM were provided by
J.P. Cline, M.H. Mendenhall, D. Black, and A. Henins of the NIST Materials Measurement Science Division, andJ.J. Ritter, formerly of NIST.
R. David Holbrook, Chief
Materials Measurement Science Division
Gaithersburg, MD 20899
Certificate Issue Date: 04 June 2021

Certificate Revision History on Last Page

SRM 1979

Steven J. Choquette, Director
Office of Reference Materials
Page 1 of 9

Use of the Advanced Photon Source (APS) at Argonne National Laboratory was supported by the U.S. Departmentof Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Certain data analysis models were implemented by P.S. Whitfield of Oak Ridge National Laboratory, TN.
TEM analysis was performed by J.E. Bonevich of the NIST Materials Science and Engineering Division.
Statistical analysis was performed by J.J. Filliben of the NIST Statistical Engineering Division.
Support aspects involved in the issuance of this SRM were coordinated through the NIST Office of Reference
Materials.
INSTRUCTIONS FOR STORAGE AND USE
Storage: SRM 1979 was bottled in an argon atmosphere. When not in use, store the unused portion of this powder
tightly capped in its original bottle, preferably in a dry atmosphere.
Use: The powder of SRM 1979 consists of aggregates of nano-crystallites. If desired, the aggregates can be broken
up to a limited extent with a kneading operation using a mortar and pestle without affecting the diffraction line shape.
SOURCE, PREPARATION, AND ANALYSIS(1)The research leading to this SRM, its preparation, characterization, and the certification method are examined inreference 4.
Material Source: The feedstock for SRM 1979 was prepared by decomposing zinc oxalate in a NIST-built vacuum
furnace [5]. The precursor zinc oxalate powder, 99.999 % pure (metals basis), was obtained from Alfa Aesar (WardHill, MA). The vacuum furnace was designed specifically for this project; it can heat a large quantity of powder,under vacuum, uniformly through the temperature range of 100 °C to 500 °C. The precursor was heated in the vacuum
furnace, rapidly from room temperature to 70 °C, then from 70 °C to 110 °C at a rate of 2 °C/h followed by anotherrapid increase to 250 °C and then up to 400 °C at 2 °C/h. This material was then annealed for a second time in aconventional furnace with no atmospheric control. It was rapidly heated to a temperature of 350 °C, for the 15 nm
crystallite size, heated at a rate of 2 °C/h to a final temperature of 400 °C, while the same ramp was used for the 60 nm
crystallite size to reach a final temperature of 550 °C.
Certification Method: The certified measurement values of SRM 1979 include the area-weighted mean column
lengths, ⟨L⟩area, and the volume-weighted mean column lengths, ⟨L⟩vol, of the sample contribution to each diffraction
profile. Bertaut [6] provides a derivation of the relationship between these parameters and the Fourier transform of
the intensity of X-rays reflected from a specimen. Also certified are the lattice parameters. Informational data include
the particle size distribution measured via laser scattering and microstructural information determined from the X-ray
experiments. The data used for determination of the certified profile breadths were collected on the high-resolution
powder diffractometer located on the 11-BM beamline at the APS [7]. The data analyzed to determine the certified
lattice parameters, the verification of homogeneity and the information data on microstructure were collected on a
NIST-built divergent beam diffractometer (DBD) [8]. This machine was configured with a Johansson incident beam
monochromator and either a scintillation or position sensitive detector (PSD). The two machines utilized beamenergies of 30 keV and 8.047 keV respectively. SRM 660b Line Position and Line Shape Standard for Powder
Diffraction [9,10], consisting of lanthanum hexaboride powder, was used to determine the instrument profile
function (IPF) for both machines.
Three software packages were used in data analyses: A NIST Python code written for this project that allowed forextraction of Fourier transforms from observed profiles; the commercial code TOPAS [11] was used for the global
Pawley [12] analyses, using the fundamental parameters approach (FPA) [13], the Scardi & Leoni model for crystallite
size [14] and the Warren model for stacking faults; and lastly the NIST FPA Python Code (FPAPC) [15]. FPAPC
duplicated (and independently verified) the capabilities of TOPAS that were used for this study, but also permittedsynthesis of Fourier transforms of the diffraction line profiles from the refined parameters (from TOPAS). The linkageof the certified lattice parameter values to the fundamental unit of length, as defined by the SI [16], was establishedwith use of the emission spectrum of Cu Kα radiation as the basis for constructing the diffraction profiles. Certification
data were analyzed in the context of both Type A uncertainties, assigned by statistical analysis, and Type B(1) Certain commercial instruments, materials, or processes are identified in this certificate to adequately specify theexperimental procedure. Such identification does not imply recommendation or endorsement by the National Institute of Standards
and Technology, nor does it imply that the instruments, materials, or processes identified are necessarily the best available for the
purpose.

SRM 1979

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uncertainties, based on knowledge of the nature of errors in the measurements, to result in the establishment of robust
uncertainties for the certified values.
Certification Procedure: Ten units of SRM 1979 were removed from the population in accordance to a stratified
random protocol. These units consisted of two bottles each; one of the 15 nm material, the second of the 60 nm. For
X-ray powder diffraction analyses using the DBD, two specimens were prepared from each bottle of SRM 1979, fora total of 40 specimens. These were run on the DBD using both the scintillation detector and the PSD. Both the orderin which the specimens were prepared and the run order were randomized. Data for the measurement of lattice
parameters were collected using a zero background quartz plate for the specimen holder. Samples were prepared bykneading a small amount of material in a mortar and pestle using ethanol as a suspending agent. Small amounts ofthe suspension were transferred to the quartz plate and allowed to dry resulting in a thin film of the zinc oxide powder.
With regards to the 11-BM beamline, data were collected from five randomly selected specimens of the 15 nm material
while for 60 nm material, data were collected from four specimens. Prior to data collection on the zinc oxide, a dataset
from SRM 660b was collected, midway through the data collection, a second dataset from SRM 660b was collected,
and a third run was performed when the data collection from the zinc oxide was complete.
With the collection of X-ray powder diffraction data from the DBD, the 1.5 kW copper tube of fine focus geometry
was operated at a power of 1.2 kW. The variable divergence incident slit was also set to 0.9°, a 0.2 mm (0.05°)
receiving slit was used with the scintillation detector. Data were collected from 25° to 125° 2θ, with a step width of
0.02° 2θ for the 60 nm material, while a width of 0.025 was used with the 15 nm. Likewise, the count times were 16 s
and 20 s respectively for a total data collection time of approximately 22 h. The PSD used for this work had a pixel
width of 75 μm, and the window width was set to 4 mm. With a goniometer radius of 217 mm these values translate
to a resolution 0.02 °2θ and active scan range of 1.05 °2θ. Data were collected in “picture taking” mode wherein datafrom the PSD window were recorded individually with a combination of coarse steps, in the context of the 1.05 °2θ
window, and fine ones, in the context of 0.02 °2θ, resolution. With post data collection processing, this approachallowed for timely data collection at an effective step width of 0.005° 2θ [17]. Scan times were approximately 3.5 h.
A 1.5° Soller slit was located in front of the PSD window to limit axial divergence. Samples were spun at 0.5 Hz
during data collection. The machine was located within a temperature-controlled laboratory space where the nominal
short-range control of temperature was ± 0.1 K. The temperature and humidity were recorded during data collection
using Veriteq SP 2000 monitors stated to be accurate to ± 0.15 K. The source was allowed to equilibrate at operating
conditions for at least an hour prior to recording any certification data. The performance of the machine was qualified
with the use of SRM 660b and SRM 676a Alumina Powder (Quantitative Analysis Powder Diffraction Standard) [18]using procedures discussed in reference 8. The 11-BM data were collected from 0.5° to 62° 2θ with a step width of
0.001°; total data collection time was approximately 2 h. Capillary samples were of 0.8 mm in diameter and spunat >90 Hz during data collection.
All data were analyzed using the FPA method as implemented in TOPAS with Pawley analyses. Analysis of datafrom SRM 660b was performed as part of the calibration of the DBD that also characterized the IPF [8]. Data fromthe DBD were analyzed using the energies of the Cu Kα1 emission spectrum as characterized in reference 19. With
the data collected using the scintillation detector, the emission spectrum from the IBM was modeled with a series ofGaussian profiles; three for the Kα11 line, and a fourth for the Kα12. With the PSD data, the optics of theJohansson IBM were modeled using dynamical scattering from the monochromator in conjunction with the powder
sample as per the optics of a 2-crystal monochromator. The resulting “band pass” model provides a function which
effectively cuts off the Lorentzian tails of the native Cu Kα1 lines, providing good agreement with the shape of thetails of the observed diffraction profiles. It also adds a dispersion term to the FPA emission model which adds to thewidth of the modeled lines, further improving the fit to the observation [20]. Parameters associated with the bandpass
model, as well as others of the IPF, the incident slit angle and the Soller slit angles of the “full” axial divergencemodel [21] were refined using scans from SRM 660b. They were then fixed at the SRM 660b values for the analysesof SRM 1979.
The IPF of the 11-BM machine was also modeled with an FPA analysis of SRM 660b. The lattice parameters values
were fixed to the certified values. The incident beam spectrum of the 11-BM machine was modeled using threeGaussian profiles with a common, refined wavelength; breadths and intensities were refined independently. The
incident beam was considered parallel in the equatorial plane. The “full” axial divergence model [21] was used withthe two Soller slit values being refined as a single value. This is not technically correct as the 11-BM machine is not
symmetric in the context of the incident vs. diffracted beam path lengths. A quality fit was obtained nonetheless;other, more complex modes of refinement were tested with no improvement. With their refinement, the lengths of the“filament”, sample and “receiving slit” were constrained to a common value. Refinements of SRM 660b included amodel to account for crystallite size broadening. While this broadening was nearly undetectable for the DBD, it
amounted to a substantial portion of the apparent IPF for the 11-BM machine. This crystallite size broadening was
not included in subsequent analyses involving the 11-BM IPF, as its true IPF would not include the contributions fromthe standard. The refined parameters obtained from these analyses of SRM 660b were used as the input data with
SRM 1979

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FPAPC to compute the Fourier transforms of the IPF at the locations of the ZnO profiles. With this approach, the IPF
transforms are noiseless as they are calculated from a theoretical model. However, they do contain the systematic
errors that are, in turn, the result of systematic errors of the FPA.
The 11-BM data were analyzed with the a NIST Python code in order to extract the Fourier transforms of thediffraction profiles [22]. This procedure involved a two-step process: the profiles were fit with a Voigt function withthe weighting set to favor the fitting of the background, the second involving determining the transform of theresiduals. In normal least-squares fitting, one weights the data with 𝑤𝑤 = 1⁄𝜎𝜎 2 = 1⁄𝑦𝑦, where y is the number ofcounts per bin. With this analysis, the data are weighted with 𝑤𝑤 = 1⁄(𝑦𝑦0 + 𝑦𝑦 + 𝑎𝑎2 𝑦𝑦 2 ) wherein y0 is a few counts(to avoid divide-by-zero errors), and 𝑎𝑎 is a parameter that can be varied to increase/decrease the weighting towards
the background, typically set to 0.1. With this procedure, an accurate model of the tail region at the expense of the fit
in center of each profile was obtained. The residuals are then individually fit with trigonometric functions that map
directly into a Fourier series. The Fourier transforms of the observed profiles can then be computed directly. The
deconvolution of the IPF from the observed profiles was performed by division, with the NIST Python code, to yield
the desired transforms of the sample broadened profiles. Throughout this procedure the statistical errors associatedwith the original least-squares fits were propagated through to the transforms themselves. Transforms were fit withan analytical function consistent with a log-normal crystallite size distribution to yield the certified MCL
values: ⟨L⟩area and ⟨L⟩vol.

The FPA analyses of SRM 1979 were carried out with the procedures outlined in reference 8. The crystallite size
broadening was modeled with a log-normal size distribution of spherical crystallites using the Scardi and Leoni
formalism, and the stacking faults were modeled as per Warren, microstrain was modeled with a Lorentzian profile
varying in tan θ. Individual analyses of the DBD data collected with the scintillation detector were performed forhomogeneity testing with respect to lattice parameter values. The data from 11-BM, and that collected from the DBD
configured with the PSD, were analyzed with global Pawley analyses. There were four such refinements: two for the
15 nm data from each instrument and the analogous two for the 60 nm data. The refined parameters pertinent to themicrostructure are shown in Table 5 as information values. Equations developed by Krill and Birringer [23] wereused to compute the MCL values shown in Table 5 from the refined parameters of the log-normal distribution.
Individual Pawley analyses of the DBD data collected with the PSD were used to generate median and breadthparameters of a log-normal distribution used for homogeneity testing. The certified lattice parameters were obtained
from independent analyses of data from specimens mounted as thin films of zinc oxide powder; the sample attenuation
function was not included in these analyses. The refined lattice parameters were adjusted using the coefficient ofthermal expansion values found in Touloukian et al. [24] to values at 22.5 °C.

Certified Values and Uncertainties: The certified values for MCL of the two powders are shown in Tables 1 and 2.
FPAPC was used to export the Fourier transforms of the profiles obtained from the refined parameters shown in
Table 5. These were then analyzed in an analogous manner as the certified data to yield a second set of MCL values
that would correspond to the those obtained with the global FPA Pawley fits using TOPAS. The type B errors wereassessed with a graphical comparison of these data to the certified values. The trends observed indicated a
15 % uncertainty was appropriate for the ⟨L⟩area values while the uncertainty for the ⟨L⟩vol MCL values was 10 %. Theinterval defined by the certified value and its uncertainty represents an expanded uncertainty using k = 2, in the absenceof systematic error, and was calculated according to the method described in the ISO/JCGM Guide [3]. The
measurand is the MCL, area, and volume weighted. The certified values for lattice parameters are provided inTables 3 and 4. The measurand is the lattice parameters obtained with TOPAS. The components of uncertainty thatwere evaluated as Type B uncertainties were considered primarily in the context of the uniformity in lattice parameteras a function of 2θ angle; this, in turn, would reflect the functionality of the FPA model. Type A + B uncertainties(statistical + systematic) are shown in Tables 3 and 4.

SRM 1979

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Table 1. Certified Mean Column Length Values for the 15 nm Zinc Oxide of SRM 1979
(Peak Position Information Values Computed from Certified Lattice Parameters and Cu Kα1 = 0.154 059 29 nm)
2θ
(°)
31.77034.40936.25247.53156.59862.84066.37967.94269.08872.53676.95581.35789.59992.79895.31098.591102.931104.088
107.410110.394116.263
121.563hkl
010(a)
002(a)
011
012
110(a)
013
020(a)
112(a)
021
004(a)
022
014
023
210(a)
211
114(a)
212
015
024
030(a)
213
032(a)⟨L⟩area
(nm)
18.4
18.9
14.7
8.3
19.2
11.2
16.4
16.1
15.5
18.8
9.4
7.8
11.1
14.1
13.2
13.6
9.4
10.3
8.5
14.3
10.8
13.6

Type A(k = 2)Type A + B(k = 2)± 0.22± 0.22± 0.18± 0.11± 0.65± 0.13± 0.81± 0.21± 1.05± 0.91± 0.12± 0.59± 0.09± 0.11± 0.12± 0.12± 0.14± 0.87± 0.35± 0.22± 0.11± 0.30

± 3.0
± 3.1
± 2.4
± 1.4
± 3.5
± 1.8
± 3.3
± 2.6
± 3.4
± 3.7
± 1.5
± 1.8
± 1.8
± 2.2
± 2.1
± 2.2
± 1.6
± 2.4
± 1.6
± 2.4
± 1.7
± 2.3

⟨L⟩vol
(nm)
26.5
28.6
23.5
16.3
26.1
20.1
24.7
24.8
23.4
26.7
17.8
14.5
19.7
22.9
22.0
23.3
17.8
18.7
15.3
22.9
19.4
22.3

Type A(k = 2)Type A + B(k = 2)± 0.22± 0.16± 0.22± 0.24± 0.17± 0.17± 0.31± 0.13± 0.44± 0.31± 0.19± 0.35± 0.18± 0.21± 0.11± 0.12± 0.20± 0.30± 0.36± 0.08± 0.15± 0.20

± 2.9
± 3.0
± 2.6
± 1.9
± 2.8
± 2.2
± 2.8
± 2.6
± 2.8
± 3.0
± 2.0
± 1.8
± 2.2
± 2.5
± 2.3
± 2.5
± 2.0
± 2.2
± 1.9
± 2.4
± 2.1
± 2.4

(a) Breadth unaffected by stacking faults.

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Table 2. Certified Mean Column Length Values for the 60 nm Zinc Oxide of SRM 1979
(Peak Position Information Values Computed from Certified Lattice Parameters and Cu Kα1 = 0.154 059 29 nm)
2θ
(°)
31.76634.41936.25147.53556.59162.85266.37167.94269.08172.55976.95381.37789.60492.78495.29898.608102.923104.122107.425110.375
116.262121.549hkl
010(a)
002(a)
011
012
110(a)
013
020(a)
112(a)
021
004(a)
022
014
023
210(a)
211
114(a)
212
015
024
030(a)
213
032(a)⟨L⟩area
(nm)
76.1
75.5
67.7
39.6
71.6
52.1
57.6
63.7
61.1
63.3
44.5
34.4
50.0
48.5
49.4
49.9
41.9
45.8
37.4
56.3
44.6
50.9

Type A(k = 2)Type A + B(k = 2)± 4.11± 0.95± 0.72± 0.55± 0.56± 4.34± 5.35± 0.62± 0.45± 0.96± 4.19± 3.04± 0.69± 0.44± 4.39± 4.44± 3.78± 0.26± 3.07± 0.60± 3.84± 0.54± 15.5± 12.3± 10.9± 6.5± 11.3± 12.2± 14.0± 10.2± 9.6± 10.5± 10.9
± 8.2
± 8.2
± 7.7
± 11.8± 11.9± 10.1
± 7.1
± 8.7
± 9.0
± 10.5± 8.2⟨L⟩vol
(nm)
112.4
106.0
101.7
76.0
106.5
84.0
97.0
97.7
96.6
95.9
79.1
66.7
82.0
88.7
87.4
85.2
76.6
75.8
67.0
89.6
78.5
86.0

Type A(k = 2)Type A + B(k = 2)± 1.59± 1.42± 1.40± 1.19± 1.26± 2.03± 3.22± 1.25± 1.06± 1.49± 1.72± 2.00± 0.92± 1.28± 2.24± 1.77± 2.03± 1.12± 1.99± 0.72± 2.05± 1.71± 12.8± 12.0± 11.6± 8.8± 11.9± 10.4± 12.9± 11.0± 10.7± 11.1
± 9.6
± 8.7
± 9.1
± 10.2± 11.0± 10.3
± 9.7
± 8.7
± 8.7
± 9.7
± 9.9
± 10.3(a) Breadth unaffected by stacking faults.

Table 3. Certified Lattice Parameter Values for SRM 1979
(15 nm material)acLattice Parameter(nm)

Type A(k = 2)Type A + B(k = 2)0.324 966 40.520 833 0± 0.000 004 6± 0.000 017 2± 0.000 030± 0.000 030

Table 4. Certified Lattice Parameter Values for SRM 1979
(60 nm material)ac

SRM 1979

Lattice Parameter(nm)

Type A(k = 2)Type A + B(k = 2)0.324 982 8
0.520 675 0± 0.000 007 5± 0.000 012 4± 0.000 020± 0.000 020

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Information Values and Uncertainties: The refined parameters obtained from the FPA Pawley analyses included
those that defined the microstructure of the zinc oxide. These values are considered model dependent and, therefore,
more prone to bias than the certified MCL values. These are shown in Table 5. The information values for the particle
size distributions, as determined by laser scattering, are given in Figures 1 and 2. TEM analysis confirmed thepresence and nature of the stacking faults. Also indicated was that the particles of the 15 nm zinc oxide were
aggregates of the 15 nm crystallites displaying a clear texture. It was concluded that this texture was reminiscent of
the larger parent crystals of zinc oxalate which upon decomposition formed the poly-crystalline aggregates.
Table 5. Refined Microstructural Parameter Information Values for SRM 1979
15 nm
Parameter⟨L⟩area (nm)⟨L⟩vol (nm)median diameter (nm)distribution width σ
deformation α
stacking fault β
strain ε0 / 10-6
χ2 ⁄𝑁𝑁 (GoF)

11-BM
23.83(6)31.39(9)24.11(4)0.397(1)0.001 21(2)0.012 59(5)200(2)
1.11

60 nm
DBD
23.77(30)31.65(46)23.35(25)0.411(4)0.001 59(10)0.010 82(23)182(8)
1.06

11-BM
95.4(4)138.9(6)75.0(1)0.508(1)0.000 28(1)0.001 57(1)
73(1)
1.04

DBD
80.7(13)128.3(25)51.1(4)0.58(4)0.000 35(2)0.001 47(3)
12(2)
1.09

Figure 1. Typical Particle Size Distribution of 15 nm Zinc Oxide by Laser Scattering.

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Figure 2. Typical Particle Size Distribution of 60 nm Zinc Oxide by Laser Scattering.
REFERENCES[1]

Langford, J.I.; Boultif, A.; Auffrédic, J.P.; Louër, D.; The Use of Pattern Decomposition to Study the Combined
X-ray Diffraction Effects of Crystallite Size and Stacking Faults in Ex-Oxalate Zinc Oxide; J. Appl. Cryst.,
Vol. 26(1), pp. 22–33 (1993).
[2] Warren, B.E.; X-ray Diffraction; Addison-Wesley: Reading, MA (1969).
[3] JCGM 100:2008; Evaluation of Measurement Data — Guide to the Expression of Uncertainty in Measurement(GUM 1995 with Minor Corrections); Joint Committee for Guides in Metrology (JCGM) (2008); available athttps://www.bipm.org/en/publications/guides (accessed Jun 2021); see also Taylor, B.N.; Kuyatt, C.E.;
Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results; NIST Technical
Note 1297; U.S. Government Printing Office:Washington, DC (1994); available athttps://www.nist.gov/pml/nist-technical-note-1297 (accessed Jun 2021).
[4] Cline, J.P.; Mendenhall, M.H.; Ritter, J.J.; Black, D.; Henins, A.; Bonevich, J.E.; Whitfield, P.S.; Filliben, J.J.;
The Certification of Standard Reference Material 1979: Powder Diffraction Line Profile Standard for Crystallite
Size Analysis; J. Res. Natl. Inst. Stand. Technol, Vol. 125, No. 125020 (2020).
[5] Cline, J.P.; Leoni, M.; Black, D.; Henins, A.; Bonevich, J.E.; Whitfield, P.S.; Scardi, P.; Crystalline Domain
Size and Faulting in the New NIST SRM 1979 Zinc Oxide; Pow. Diff. J., Vol. 28(S2), pp. S22–S32 (2013).
[6] Bertaut, E.F.; Raies de Debye–Scherrer et Repartition des Dimensions des Domaines de Bragg dans les Poudres
Polycristallines; Acta Cryst., Vol. 3(1), pp. 14–18 (1950).
[7] Wang, J.; Toby, B.H.; Lee, P.L.; Ribaud, L.; Antao, S.M.; Kurtz, C.; Ramanathan, M.; Von Dreele, R.B.;
Beno, M.A.; A Dedicated Powder Diffraction Beamline at the Advanced Photon Source: Commissioning and Early
Operational Results; Rev. Sci. Instrum., Vol. 79(8), pp. 085105-1–085105-7 (2008).
[8] Cline, J.P.; Mendenhall, M.H.; Black, D.; Windover, D.; Henins, A.; The Optics and Alignment of the Divergent
Beam Laboratory X-ray Powder Diffractometer and its Calibration using NIST Standard Reference Materials;
J. Res. Natl. Inst. Stand. Technol, Vol. 120, pp. 173–222 (2015).
[9] SRM 660b; Line Position and Line Shape Standard for Powder Diffraction (Lanthanum Hexaboride Powder);National Institute of Standards and Technology; U.S. Department of Commerce: Gaithersburg, MD(25 October 2015).
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Certificate Revision History: 04 June 2021 (Changes to information values in Table 5; editorial changes); 17 October 2016 (Original certificatedate).

Users of this SRM should ensure that the Certificate of Analysis in their possession is current. This can beaccomplished by contacting the SRM Program: telephone (301) 975-2200; e-mail srminfo@nist.gov; or via theInternet at https://www.nist.gov/srm.

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