BS ISO 22489-2016 Microbeam analysis Electron probe microanalysis Quantitative point analysis for bulk specimens using wavelength dispersive X-ray spectroscopy《微光束分析 电子探针微量分析 用波长色散.pdf

1、BS ISO 22489:2016Microbeam analysis Electronprobe microanalysis Quantitative point analysisfor bulk specimens usingwavelength dispersive X-rayspectroscopyBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 22489:2016 BRITISH STANDARDNational forewordThis British S

2、tandard is the UK implementation of ISO 22489:2016. It supersedes BS ISO 22489:2006 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee CII/9, Microbeam analysis.A list of organizations represented on this committee can be obtained on request to its secret

3、ary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 92670 9 ICS 71.040.99 Compliance with a British Standard cannot

4、 confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 22489:2016 ISO 2016Microbeam analysis Electron probe micr

5、oanalysis Quantitative point analysis for bulk specimens using wavelength dispersive X-ray spectroscopyAnalyse par microfaisceaux Microsonde de Castaing Analyse quantitative ponctuelle dchantillons massifs par spectromtrie dispersion de longueur dondeINTERNATIONAL STANDARDISO22489Second edition2016-

6、10-15Reference numberISO 22489:2016(E)BS ISO 22489:2016ISO 22489:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by

7、 any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 4

8、01CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 22489:2016ISO 22489:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Abbreviated terms 14 Procedure for quantification . 24.1 General procedure for quantitative microa

9、nalysis 24.1.1 Principle and procedure of quantitative microanalysis . 24.1.2 Coverage of the quantitative analysis 24.1.3 Selection of reference materials . 34.2 Specimen preparation 34.3 Calibration of the instrument . 34.3.1 Accelerating voltage 34.3.2 Probe current 34.3.3 X-ray spectrometer 34.3

10、.4 Dead time . 44.4 Analysis conditions . 44.4.1 Accelerating voltage 44.4.2 Probe current 44.4.3 Analysis position 44.4.4 Probe diameter 54.4.5 Scanning the focused electron beam 54.4.6 Specimen surface . 54.4.7 Selection of X-ray line 54.4.8 Spectrometer . 54.4.9 Method for measurement of X-ray pe

11、ak intensity 64.4.10 Method for measurement of background intensity . 64.5 Correction method based on analytical models . 64.5.1 Principles 64.5.2 Correction models 74.6 Calibration curve method 74.6.1 Principle 74.6.2 Selection of reference materials . 84.6.3 Procedure . 84.7 Uncertainty . 85 Test

12、report . 8Annex A (informative) Physical effects and correction 10Annex B (informative) Outline of various correction techniques .12Annex C (informative) Measurement of the k-ratios in case of “chemical effects” 14Bibliography .15 ISO 2016 All rights reserved iiiContents PageBS ISO 22489:2016ISO 224

13、89:2016(E)ForewordISO (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

14、which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on al

15、l 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. Th

16、is 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

17、 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

18、and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL

19、: www.iso.org/iso/foreword.html.The committee responsible for this document is ISO/TC 202, Microbeam analysis, Subcommittee SC 2, Electron probe microanalysis.This second edition cancels and replaces the first edition (ISO 22489:2006), of which it constitutes a minor revision to update the reference

20、s and to revise text in 4.4.1 and 4.4.8. iv ISO 2016 All rights reservedBS ISO 22489:2016ISO 22489:2016(E)IntroductionElectron probe microanalysis is widely used for the quantitative analysis of elemental composition in materials. It is a typical instrumental analysis and the electron probe microana

21、lyser has been greatly improved to be user friendly. Obtaining accurate results with this powerful tool requires that it be properly used. In order to obtain reliable data, however, optimum procedures must be followed. These procedures, such as preparation of specimens, measurement of intensities of

22、 characteristic X-rays and calculations of concentrations calculated from X-ray intensities, are given for use as standard procedures in this International Standard. ISO 2016 All rights reserved vBS ISO 22489:2016BS ISO 22489:2016Microbeam analysis Electron probe microanalysis Quantitative point ana

23、lysis for bulk specimens using wavelength dispersive X-ray spectroscopy1 ScopeThis International Standard specifies requirements for the quantification of elements in a micrometre-sized volume of a specimen identified through analysis of the X-rays generated by an electron beam using a wavelength di

24、spersive spectrometer (WDS) fitted either to an electron probe microanalyser or to a scanning electron microscope (SEM).This International Standard also describes the following: the principle of the quantitative analysis; the general coverage of this technique in terms of elements, mass fractions an

25、d reference specimens; the general requirements for the instrument; the fundamental procedures involved such as specimen preparation, selection of experimental conditions, the measurements, the analysis of these and the report.This International Standard is intended for the quantitative analysis of

26、a flat and homogeneous bulk specimen using a normal incidence beam. It does not specify detailed requirements for either the instruments or the data reduction software. Operators should obtain information such as installation conditions, detailed procedures for operation and specification of the ins

27、trument from the makers of any products used.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of

28、the referenced document (including any amendments) applies.ISO 14594, Microbeam analysis Electron probe microanalysis Guidelines for the determination of experimental parameters for wavelength dispersive spectroscopyISO 14595, Microbeam analysis Electron probe microanalysis Guidelines for the specif

29、ication of certified reference materials (CRMs)ISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratories3 Abbreviated termsEPMA electron probe microanalyserSEM scanning electron microscopeEDS energy dispersive spectrometerPHA pulse height analyserP/B peak-to

30、-background ratioINTERNATIONAL STANDARD ISO 22489:2016(E) ISO 2016 All rights reserved 1BS ISO 22489:2016ISO 22489:2016(E)4 Procedure for quantification4.1 General procedure for quantitative microanalysis4.1.1 Principle and procedure of quantitative microanalysisThe characteristic X-ray intensities

31、from electron beam interactions with a solid are approximately proportional to the mass fraction of the elements contained within the interaction volume. By measurement of characteristic X-ray intensities, the mass fractions of the elements that compose a specimen can be determined.Quantitative anal

32、ysis is performed by comparing the intensity of a characteristic X-ray line of an element in the specimen with that from a reference material containing a known mass fraction of the element, the measurements being performed under identical experimental conditions. The relationship between intensity

33、and mass fraction is not linear over a wide mass fraction range; correction calculations for both specimen and reference material are therefore required.X-ray absorption within the specimen and the reference material results in the emitted intensities being less than the generated intensities; there

34、fore, a correction is made for this. A correction is also made for characteristic X-ray fluorescence in the analytical volume, and the effect of loss of X-ray production due to electron backscattering. When electrons enter the specimen, they lose energy due to the interactions with the constituent a

35、toms. As well as being dependent on electron energy, the rate of energy loss is a function of the mean atomic number. The matrix correction procedure, thus, has three components, corresponding to the atomic number (Z), the absorption (A) and the characteristic fluorescence (F).The accuracy of the qu

36、antitative analysis depends upon the selection of the reference materials, the specimen preparation process, the measurement conditions/method, the stability and calibration of the instrument, and the use of models for quantitative correction.4.1.2 Coverage of the quantitative analysisReference mate

37、rials and unknown specimens shall fulfil the following conditions: be stable under the action of the electron beam and stable in vacuum; have a flat surface perpendicular to the electron beam; be homogenous over the analysis volume; have no magnetic domains.For the analysis volume, see ISO 14594 (an

38、alysis area and depth and volume).It is possible to perform quantitative elemental analysis for elements with an atomic number greater than or equal to 4 (beryllium).The detection limit for quantitative analysis depends on many parameters, such as the X-ray line selected, the matrix and the operatin

39、g conditions (beam intensity, accelerating voltage and counting parameters). It varies from a few parts per million (ppm) to a few hundred ppm.NOTE 1 Detection limits are covered in ISO 17470.NOTE 2 For light-element analysis or strong X-ray absorption conditions, the detection limit may be above 1

40、% (i.e. B K in silicon matrix).The accuracy obtainable is governed by the mass fraction of the element, the measurement conditions and the correction calculation. It is generally considered that the relative precision and relative accuracy for major elements can be better than 1 % and 2 %, respectiv

41、ely.NOTE 3 For analysis of elements in a strongly absorbing matrix with a reference material not matched to the specimen in composition, accuracy may be significantly worse than 2 %.2 ISO 2016 All rights reservedBS ISO 22489:2016ISO 22489:2016(E)4.1.3 Selection of reference materialsThe reference ma

42、terials shall be in accordance with the specifications of ISO 14595.In general, pure elements are used, but corrections for matrix effects are minimized when the composition of the reference material is close to that of the unknown specimen.When coating of the specimen is required (see 4.2), the ref

43、erence material shall be coated under the same conditions.4.2 Specimen preparationThe specimens (reference specimen and unknown specimen) shall be clean and free of dust.The specimen surface shall be flat. If necessary, the specimen shall be embedded in a conducting medium and metallographically pol

44、ished.The specimen must have good electrical conductivity. Charging under electron beam irradiation can be avoided by coating the specimen with a very thin conductive layer of a suitable material. A conducting path shall be established between the specimen surface and the metallic specimen holder.Ca

45、rbon coating is generally used but, in particular cases (e.g. light-element analysis), other materials should be considered (Au, Al, etc.). Carbon to a thickness of about 20 nm can be used.It is recommended that both the reference material and unknown specimen be coated with the same element at the

46、same thickness.4.3 Calibration of the instrument4.3.1 Accelerating voltageIt is important to check that the accelerating voltage is correct for the quantitative analysis to be accurate.Quantification errors will occur if the accelerating voltage is not known accurately and if it is not stable. The a

47、ccelerating voltage shall therefore be calibrated and stable.NOTE If an EDS system is attached to the EPMA, the true voltage may be determined through measurement of the Duane-Hunt limit.15If an EDS system is not attached, there is no generally available calibration method. It is advisable to reques

48、t that the manufacturer periodically checks the voltage values.4.3.2 Probe currentQuantification errors will occur if the probe current is not known accurately and if its stability is low. The probe current shall therefore be accurately monitored and stable.The probe current is normally measured usi

49、ng a Faraday cup.4.3.3 X-ray spectrometerIt is necessary to confirm the accurate adjustment of the X-ray spectrometer prior to its use for measurement. This should be done for all spectrometers and all crystals by following the instructions given by the manufacturer of the instrument.The proportionality of the X-ray detector shall be checked.NOTE The proportionality of the X-ray detector is covered in ISO 14594. ISO 2016 All rights reserved 3BS ISO 22489:2016ISO 22489:2016(E)4.3.4 Dead timeIt is necessary to correct for