ISO 20720:2018

Microbeam analysis — Methods of specimen preparation for analysis of general powders using WDS and EDS

This document specifies specimen preparation methods for the analysis of particles in powders using energy-dispersive spectrometers (EDS) or wavelength-dispersive spectrometers (WDS) installed on an EPMA or SEM. The preparation methods for powder particle analysis are classified by the analytical purpose and the particle size. This document applies to inorganic particles larger than 100 nm and smaller than 100 µm in diameter. It applies only to analysis of "general" powders, which means that it excludes procedures for special applications such as forensic or trace analysis.

Analyse par microfaisceaux — Méthodes de préparation des échantillons pour l’analyse des particules

General Information

• Status: Published
• Publication Date: 17-Oct-2018
• ICS: 71.040.99 - Other standards related to analytical chemistry
• Technical Committee: ISO/TC 202 - Microbeam analysis
• Drafting Committee: ISO/TC 202 - Microbeam analysis
• Current Stage: 6060 - International Standard published
• Start Date: 18-Oct-2018
• Completion Date: 18-Oct-2018

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 20720
First edition
2018-10
Microbeam analysis — Methods of
specimen preparation for analysis of
general powders using WDS and EDS
Analyse par microfaisceaux — Méthodes de préparation des
échantillons pour l’analyse des particules
Reference number
ISO 20720:2018(E)
ISO 2018
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ISO 20720:2018(E)
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© ISO 2018

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ii © ISO 2018 – All rights reserved
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ISO 20720:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Abbreviated terms .............................................................................................................................................................................................. 1

[1]

5 Analytical purposes and methods of specimen preparation for particle analysis ...................1

5.1 Methods of specimen preparation for particle analysis ...................................................................................... 1

5.2 Description of preparation methods .................................................................................................................................... 2

5.2.1 Analysis of whole particles or surface of particles ............................................................................. 2

5.2.2 Analysis of cross-section of particles ............................................................................................................. 4

5.3 Choosing preparation methods ................................................................................................................................................ 5

6 Electric conductivity processing .......................................................................................................................................................... 6

Annex A (informative) Examples of X-ray strength dependency on tablet-forming pressure ..................7

Annex B (informative) Example of X-ray strength dependency on tablet-forming particle size ...........8

Bibliography ................................................................................................................................................................................................................................ 9

© ISO 2018 – All rights reserved iii
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ISO 20720:2018(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

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URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 202, Microbeam analysis.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
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ISO 20720:2018(E)
Introduction

Although there are many applications of electron probe microanalysis (EPMA) and scanning electron

microscopy (SEM) for powder analysis, there are some difficulties, especially in the case of individual

particle analysis, as follows:

(a) the prevention of agglomeration of particles during preparation of the specimen;

(b) the fixation of specimens, especially when there is a small amount of tiny particles, either for

surface analysis or cross-section analysis;

(c) the cross-section preparation in the case of small particles with core-shell structures;

(d) the protection of particle surfaces from damage by electron beam irradiation in cases where the

surfaces of particles are sensitive;

(e) the counteraction of charging of the specimen under electron radiation to prevent the powder from

scattering or dispersing due to electrical repulsion;

(f) the interpretation of qualitative and/or quantitative analysis results when the X-ray generation

volume is larger than that of the particles.

Even in the case of elemental compositional analysis of a powder, the specimen preparation can

affect the results of analysis, because the roughness and/or void space within a particle aggregate or

agglomerate can impact X-ray intensity.

To cope with these difficulties, the standardization of specimen preparation for particle analysis is very

important.
© ISO 2018 – All rights reserved v
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INTERNATIONAL STANDARD ISO 20720:2018(E)
Microbeam analysis — Methods of specimen preparation
for analysis of general powders using WDS and EDS
1 Scope

This document specifies specimen preparation methods for the analysis of particles in powders using

energy-dispersive spectrometers (EDS) or wavelength-dispersive spectrometers (WDS) installed on

an EPMA or SEM. The preparation methods for powder particle analysis are classified by the analytical

purpose and the particle size.

This document applies to inorganic particles larger than 100 nm and smaller than 100 µm in diameter.

It applies only to analysis of “general” powders, which means that it excludes procedures for special

applications such as forensic or trace analysis.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Abbreviated terms
EDS energy-dispersive X-ray spectroscopy/spectrometry
EPMA electron probe microanalysis/electron probe microanalyzer
SEM scanning electron microscopy/scanning electron microscope
WDS wavelength-dispersive X-ray spectroscopy/spectrometry/spectrometer
5 Analytical purposes and methods of specimen preparation for particle
[1]
analysis
5.1 Methods of specimen preparation for particle analysis

The following methods of specimen preparation are widely used for particle analysis (see Figure 1).

The specific procedure is indicated in 5.2.

This list is not comprehensive and does not preclude the use of other specimen preparation methods for

particle analysis that can be more appropriate in some cases.
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ISO 20720:2018(E)
Figure 1 — Methods of specimen preparation for particle analysis
5.2 Description of preparation methods
5.2.1 Analysis of whole
...