IEC TS 62607-6-17:2023

Nanomanufacturing - Key control characteristics - Part 6-17: Graphene-based material - Order parameter: X-ray diffraction and transmission electron microscopy

IEC TS 62607-6-17:2023 establishes a standardized method to determine the key control characteristic order parameter for graphene-based material and layered carbon material by X-ray diffraction (XRD) and transmission electron microscopy.
The order parameter is analysed from two perspectives: z-axis and x-y-axis. In the z-axis the order parameter is derived from the full width at half maximum (FWHM) of peak (002) in the XRD spectrum. In the x-y-axis, it is derived from the FWHM of peak (100) corresponding to diffraction patterns obtained by SAED (selected area electron diffraction) technique, which is routinely performed on most transmission electron microscopes in the world.
The method is applicable for graphene-based material and layered carbon material including graphite, expanded graphite, amorphous carbon, vitreous carbon or glassy carbon, the structures of which are clarified by other characterization techniques.
The method is applicable for differentiating few-layer graphene or reduced graphene oxide from layered carbon material.
Typical application area is quality control in manufacturing to ensure batch-to-batch reproducibility.
NOTE Graphene oxide, one type of graphene-based material, is not within the scope of this document.

General Information

• Status: Published
• Publication Date: 02-May-2023
• ICS: 07.120 - Nanotechnologies
• Technical Committee: TC 113 - Nanotechnology for electrotechnical products and systems
• Drafting Committee: WG 8 - TC 113/WG 8
• Current Stage: PPUB - Publication issued
• Start Date: 06-Jun-2023
• Completion Date: 03-May-2023

Standards Content (Sample)

IEC TS 62607-6-17
®

Edition 1.0 2023-05
TECHNICAL
SPECIFICATION

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Nanomanufacturing – Key control characteristics –
Part 6-17: Graphene-based material – Order parameter: X-ray diffraction and
transmission electron microscopy

IEC TS 62607-6-17:2023-05(en)

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IEC TS 62607-6-17

®


Edition 1.0 2023-05




TECHNICAL



SPECIFICATION








colour

inside










Nanomanufacturing – Key control characteristics –

Part 6-17: Graphene-based material – Order parameter: X-ray diffraction and

transmission electron microscopy
























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ICS  07.120 ISBN 978-2-8322-6941-1




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– 2 – IEC TS 62607-6-17:2023  IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
3.1 General terms . 8
3.2 Key control characteristics measured in accordance with this document . 9
3.3 Terms related to the measurement method . 10
4 General . 11
4.1 Measurement principle . 11
4.2 Sample preparation method . 11
4.3 Description of measurement equipment and apparatus . 12
4.3.1 XRD equipment . 12
4.3.2 TEM equipment . 12
4.4 Supporting materials . 12
4.5 Ambient conditions during measurement . 12
5 Measurement procedure . 13
5.1 Calibration of measurement equipment . 13
5.2 Detailed protocol of the measurement procedure . 13
5.3 Measurement uncertainty source . 14
6 Data analysis . 14
7 Results to be reported . 15
7.1 General . 15
7.2 Product or sample identification . 15
7.3 Test conditions . 15
7.4 Measurement specific information . 15
7.4.1 Detailed explanation of the XRD measurement . 15
7.4.2 Detailed explanation of the TEM measurement . 16
7.5 Test results . 16
Annex A (informative) Format of the test report . 17
Annex B (informative) Case study: Measurement and data analysis . 20
B.1 Data analysis of XRD measurements . 20
B.2 Data analysis of TEM measurements . 21
B.3 Calculation of order parameter . 22
Bibliography . 24

Figure 1 – Different packing configurations of graphene layers in graphite powder and
graphene powder . 6
Figure 2 – A flow chart illustrating the cases when TEM measurement is needed . 14
Figure B.1 – d-spacing versus intensity of HOPG and the fitting result of peak (002) . 20
Figure B.2 – The fitting results of peak (002) of different samples . 21
Figure B.3 – The fitting results of peak (100) of amorphous carbon sample. 21
Figure B.4 – The fitting results of peak (100) of different samples . 22
Figure B.5 – The diagram of graphene area determined by order parameter . 23

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IEC TS 62607-6-17:2023  IEC 2023 – 3 –
Table A.1 – Product identification (in accordance with the relevant blank detail
specification) . 17
Table A.2 – General material description (in accordance with the relevant blank detail

specification) . 17
Table A.3 – Information related to XRD test . 18
Table A.4 – Information related to TEM test . 18
Table A.5 – Measurement results . 19
Table B.1 – Order parameters of different samples . 22

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– 4 – IEC TS 62607-6-17:2023  IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

NANOMANUFACTURING –
KEY CONTROL CHARACTERISTICS –

Part 6-17: Graphene-based material –
Order parameter: X-ray diffraction and transmission electron microscopy

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC TS 62607-6-17 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/700/DTS 113/746/RVDTS

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.

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IEC TS 62607-6-17:2023  IEC 2023 – 5 –
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC TS 62607 series, published under the general title
Nanomanufacturing – Key control characteristics, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The "colour inside" logo on the cover page of this document indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

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– 6 – IEC TS 62607-6-17:2023  IEC 2023
INTRODUCTION
Graphite is composed of layers of carbon atoms just a single atom in thickness, known as
graphene layers, to which it owes many of its remarkable properties. When the thickness of
graphite flakes is reduced to just a few graphene layers, some of the material's technologically
most important characteristics are greatly enhanced. In other words, graphene is more than just
graphite. Although graphene has a vast number of potential applications, a survey of
commercially available graphene samples reveals that research could be undermined by the
1
poor quality of the available material [1] . Many highly priced graphene products from 60
producers consist mostly of graphite powder [2]. Therefore, a lack of classification standards is
creating a situation that downstream users are afraid to use graphene because they do not
know whether the graphene is fake.
Figure 1 shows the schematic packing configurations of graphene layers in graphite powder
(left side of Figure 1) and graphene powder (right side of Figure 1) and their corresponding
SEM images. It can be seen that graphite can be formed regularly in the z-axis, but graphene
powder is assembled like house-of-card-type stacking, which is formed by graphene layers in
a disorderly way in 3D space. For other carbon-related materials – for example, amorphous
carbon, glassy carbon, expanded graphite – their packing configurations differ from those of
graphite and graphene. An order parameter which indicates the order degree of a system can
be employed to classify different carbon-related materials.

Figure 1 – Different packing configurations of graphene layers
in graphite powder and graphene powder
This document establishes a method for determining the order parameter of graphene-based
material and carbon material. The order parameter can be analysed from the z-axis and x-y-axis,
respectively. The former can be derived from X-ray diffraction (XRD) spectra based on Bragg
diffraction, and the latter can be derived from the diffraction patterns by selected area electron
diffraction (SAED) technique, which is performed on a transmission electron microscope (TEM)
with very high-resolution imaging. Since thermal temperature can lead to re-graphitization, the
FWHM of peak (002) in the XRD spectrum indicates the quality of thermally reduced graphene
powder [3]. Therefore, the order parameter can be an index of production uniformity of
graphene-based materials, and also relates the materials' application with respect to heat
dissipation.


___________
1
 Numbers in square brackets refer to the Bibliography.

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IEC TS 62607-6-17:2023  IEC 2023 – 7 –
NANOMANUFACTURING –
KEY CONTROL CHARACTERISTICS –

Part 6-17: Graphene-based material –
Order parameter: X-ray diffraction and transmission electron microscopy



1 Scope
This part of IEC TS 62607 establishes a standardized method to determine the key control
characteristic
– order parameter
for graphene-based material and layered carbon material by
– X-ray diffraction (XRD) and transmission electron microscopy.
The order parameter is analysed from two perspectives: z-axis and x-y-axis. In the z-axis the
order parameter is derived from the full width at half maximum (FWHM) of peak (002) in the
XRD spectrum. In the x-y-axis, it is derived from the FWHM of peak (100) corresponding to
diffraction patterns obtained by SAED (selected area electron diffraction) technique, which is
routinely performed on most transmission electron microscopes in the world.
– The method is applicable for graphene-based material and layered carbon material including
graphite, expanded graphite, amorphous carbon, vitreous carbon or glassy carbon, the
structures of which are clarified by other characterization techniques.
– The method is applicable for differentiating few-layer graphene or reduced graphene oxide
from layered carbon material.
– Typical application area is quality control in manufacturing to ensure batch-to-batch
reproducibility.
NOTE Graphene oxide, one type of graphene-based material, is not within the scope of this document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

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– 8 – IEC TS 62607-6-17:2023  IEC 2023
3.1 General terms
3.1.1
graphene
graphene layer
single layer graphene
monolayer graphene
single layer of carbon atoms with each atom bound to three neighbours in a honeycomb
structure
Note 1 to entry: It is an important building block of many carbon nano-objects.
Note 2 to entry: As graphene is a single layer, it is also sometimes called monolayer graphene or single-layer
graphene and abbreviated as 1LG to distinguish it from bilayer graphene (2LG) and few-layer graphene (FLG).
Note 3 to entry: Graphene has edges and can have defects and grain boundaries where the bonding is disrupted.
[SOURCE: ISO/TS 80004-13:2017, 3.1.2.1]
3.1.2
graphene-based material
GBM
graphene material grouping of carbon-based 2D materials that include one or more of graphene,
bilayer graphene, few-layer graphene, graphene nanoplate, and functionalized variations
thereof as well as graphene oxide and reduced graphene oxide
Note 1 to entry: "Graphene material" is a short name for graphene-based material.
3.1.3
few-layer graphene
FLG
two-dimensional material consisting of three to ten well-defined stacked graphene layers
[SOURCE: ISO/TS 80004-13:2017, 3.1.2.10]
3.1.4
reduced graphene oxide
rGO
reduced oxygen content form of graphene oxide
Note 1 to entry: This can be produced by chemical, thermal, microwave, photo-chemical, photo-thermal or
microbial/bacterial methods or by exfoliating reduced graphite oxide.
Note 2 to entry: If graphene oxide was fully reduced, then graphene would be the product. However, in practice,
3 2
some oxygen containing functional groups will remain and not all sp bonds will return back to sp configuration.
Different reducing agents will lead to different carbon to oxygen ratios and different chemical compositions in reduced
graphene oxide.
Note 3 to entry: It can take the form of several morphological variations such as platelets and worm-like structures.
[SOURCE: ISO/TS 80004-13:2017, 3.1.2.14]
3.1.5
graphite
allotropic form of the element carbon, consisting of graphene layers stacked parallel to each
other in a three-dimensional, crystalline, long-range order
Note 1 to entry: Adapted from the definition in the IUPAC Compendium of Chemical Terminology.
Note 2 to entry: There are two primary allotropic forms with different stacking arrangements: hexagonal and
rhombohedral.
[SOURCE: ISO/TS 80004-13:2017, 3.1.2.2]

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IEC TS 62607-6-17:2023  IEC 2023 – 9 –
3.1.6
highly oriented pyrolytic graphite
HOPG
highly pure and ordered form of synthetic graphite
Note 1 to entry: HOPG is often used as reference material for calibration of measurement equipment.
3.1.7
amorphous carbon
carbon material without long-range crystalline order
Note 1 to entry: Adapted from the definition in the IUPAC Compendium of Chemical Terminology.
Note 2 to entry: Short-range order exists, but with deviations of the interatomic distances or interbonding angles
with respect to the graphite lattice as well as to the diamond.
3.1.8
expanded graphite
modified graphite that has a layered structure with interlayer spacing
3.1.9
vitreous carbon
form of carbon derived through solid-phase carbonization from a preform comprising an
appropriate highly cross-linked polymer
Note 1 to entry: Vitreous carbon is characterized by a pseudo-amorphous, isotropic structure with low density, and
non-permeability for gases.
[SOURCE: ISO 20507:2022, 3.2.79]
3.1.10
key control characteristic
KCC
key performance indicator
material property or intermediate product characteristic which can affect safety or compliance
with regulations, fit, function, performance, quality, reliability or subsequent processing of the
final product
Note 1 to entry: The measurement of a key control characteristic is described in a standardized measurement
procedure with known accuracy and precision.
Note 2 to entry: It is possible to define more than one measurement method for a key control characteristic if the
correlation of the results is well-defined and known.
3.2 Key control characteristics measured in accordance with this document
3.2.1
order parameter
normalized parameter that indicates the degree of order of a system
Note 1 to entry: Adapted from the definition in the IUPAC Compendium of Chemical Terminology.
Note 2 to entry: An order parameter of 0 indicates disorder; the absolute value in the ordered state is 1.
Note 3 to entry: The order parameter includes z-axis order parameter and x-y-axis order parameter.

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– 10 – IEC TS 62607-6-17:2023  IEC 2023
3.3 Terms related to the measurement method
3.3.1
X-ray diffraction
XRD
method to obtain crystallographic information about a sample by observing the diffraction
pattern due to an X-ray beam hitting a sample
Note 1 to entry: The method can be used to estimate the size of coherent scattering regions.
[SOURCE: ISO 80004-6:2013, 5.2.1]
3.3.2
transmission electron microscope
TEM
instrument that produces magnified images or diffraction patterns of the sample by an electron
beam which passes through the sample and interacts with it
[SOURCE: ISO 29301:2017, 3.34, modified – In the definition, "specimen" has been replaced
by "sample".]
3.3.3
selected area electron diffraction
SAED
technique in which the crystalline structure of a sample area selected by an aperture is
examined by the diffraction of transmitted electrons resulting in a diffraction pattern
Note 1 to entry: The electrons used typically have energies of 10 keV to 200 keV.
Note 2 to entry: The diffraction pattern represents an image of the reciprocal lattice and therefore contains
information about crystal structure.
[SOURCE: ISO 80004-6:2021, 6.3.3]
3.3.4
full width at half maximum
FWHM
measure of the width of an X-ray peak in which the background is first removed to reveal the
complete peak profile
Note 1 to entry: FWHM is determined by measuring the width at half the maximum height.
[SOURCE: ISO 22309:2011, 3.16]
3.3.5
lattice spacing
d-spacing
lattice plane spacing
distance between adjacent parallel crystallographic lattice planes
[SOURCE: ISO 21432:2019, 3.20]

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IEC TS 62607-6-17:2023  IEC 2023 – 11 –
3.3.6
Bragg diffraction
width between the wavelength of light and the width of crystal structure, or relationship between
the reflecting surface and the angle formed by the ray
Note 1 to entry: The formula is 2dsinθ = nλ
where
d is the width of periodic structure;
θ is the angle between the crystal plane and incident light;
λ is the wavelength of light;
n is the constant.
[SOURCE: ISO 22278:2020, 3.4]
3.3.7
2 theta
2θ
angle of the detected X-ray beam with respect to the incident X-ray beam direction
[SOURCE: ISO 22278:2020, 3.9]
3.3.8
diffraction pattern
distribution of light due to diffraction, which depends on the geometrical and optical properties
of the object, the aberrations of the lens and the shape of its exit pupil, and the wavelength of
the light
Note 1 to entry: Also misused as the angle between the direction of an incident optical radiation beam to a diffractive
optical element and the direction of any resulting diffracted optical radiation beam.
[SOURCE: ISO 10934:2020, 3.1.41.1, modified – Note 1 to entry has been added.]
4 General
4.1 Measurement principle
XRD works by irradiating a material with incident X-rays and then measuring the intensities and
scattering angles of the X-rays that leave the material. With the obtained spectrum, one can get
information on the FWHM corresponding to peak (002) in the XRD spectrum. Using HOPG as
a reference sample, the order parameter of tested sample in z-axis can be derived from the
FWHM ratio of HOPG and tested sample.
When an energetic electron beam is incident upon a thin sample in a TEM, a diffraction pattern,
(e.g. diffraction spot, diffraction ring) will be produced in the back focal plane of the objective
lens. This pattern is magnified by the intermediate and projector lenses, then displayed on a
viewing screen and recorded [4]. This pattern can also be displayed on a monitor if the TEM is
equipped with a digital camera system. One can obtain information on corresponding interplanar
spacing and diffraction intensity from the diffraction patterns. Also the FWHM corresponding to
peak (100) is available. Using amorphous carbon as a reference sample, the order parameter
of tested sample in x-y-axis can be derived from one minus the FWHM ratio of tested sample
and amorphous carbon.
4.2 Sample preparation method
As for XRD measurement, take an appropriate amount of powder sample with a spoon and
deposit it in the groove of a sample loader. Gently press the sample with a glass slide so that
the sample surface is as flat as possible. The centre of the groove in the sample loader should
be covered by powder sample.

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– 12 – IEC TS 62607-6-17:2023  IEC 2023
As for TEM measurement, disperse an appropriate amount of tested sample in absolute ethanol,
and shake the mixture for 15 minutes with an ultrasonic machine at a power of 120 W and
frequency of 40 Hz. Then suck 2 μl dispersed mixture with a micropipette and drop it onto a
support grid. Finally leave it to dry naturally for one hour prior to TEM measurement.
4.3 Description of measurement equipment and apparatus
4.3.1 XRD equipment
4.3.1.1 X-ray generator
Device which generates an X-ray beam of fixed intensity. Different target materials (i.e. Cu, Cr,
Co, Fe, Mo) correspond to different wavelengths in Bragg diffraction.
4.3.1.2 Monochromator
When X-rays having diverse wavelengths are incident on a sample, a diffraction peak
broadening occurs, disrupting interpretation of the diffraction peak. For this reason, a
monochromator that takes only one ray from incident X-rays to make a single wavelength shall
be used for accurate diffraction tests with high resolution.
4.3.1.3 Goniometer
Device designed for the sample to move in the x-axis, y-axis and z-axis. A mechanically well-
aligned and state X-ray goniometer is required.
4.3.2 TEM equipment
4.3.2.1 Facilities for sa
...