BS ISO 22309-2011 Microbeam analysis Quantitative analysis using energy-dispersive spectrometry (EDS) for elements with an atomic number of 11 (Na) or above《光束分析 对带有11(纳)及以上的原子序数元素.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 22309:2011Microbeam analysis Quantitative analysis using energy-dispersive spectrometry (EDS) for elements with an atomic number of 11 (Na) or aboveBS ISO 22309:2011 BRITI

2、SH STANDARDNational forewordThis British Standard is the UK implementation of ISO 22309:2011. It supersedes BS ISO 22309:2006, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e C I I / 9 , M i c r o b e a m a n a l y s i s .A list of orga

3、nizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 73915 6 ICS 71.040.99 Compliance with a British Stan

4、dard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 22309:2011Microbeam analysis Quantitative analysis using

5、energy-dispersive spectrometry (EDS) for elements with an atomic number of 11 (Na) or aboveAnalyse par microfaisceaux Analyse lmentaire quantitative par spectromtrie slection dnergie (EDS) des lments ayant un numro atomique de 11 (Na) ou plus ISO 2011Reference numberISO 22309:2011(E)Second edition20

6、11-10-15ISO22309INTERNATIONAL STANDARDBS ISO 22309:2011ISO 22309:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and mi

7、crofilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in Switzerlandii ISO 2011 Al

8、l rights reservedBS ISO 22309:2011ISO 22309:2011(E) ISO 2011 All rights reserved iiiContents PageForeword ivIntroduction . v1 Scope 12 Normative references .13 Terms and definitions .24 Specimen preparation 55 Preliminary precautions 66 Analysis procedure .77 Data reduction 97.1 General .97.2 Identi

9、fication of peaks 97.3 Estimation of peak intensity .97.4 Calculation of k-ratios 107.5 Matrix effects 107.6 Use of reference materials 107.7 Standardless analysis 107.8 Uncertainty of results .117.9 Reporting of results 12Annex A (informative) The assignment of spectral peaks to their elements 13An

10、nex B (informative) Peak identity/interferences 15Annex C (informative) Factors affecting the uncertainty of a result .17Annex D (informative) Analysis of elements with atomic number 10.Guidance on the analysis of light elements with Z 10) in the specimen, its concentration can be determined by summ

11、ing the appropriate proportions of concentrations of the other elements. This is often used for the analysis of oxygen in silicate mineral specimens.c) Calculation of concentration by difference where the light element percentage is 100 % minus the percentage sum of the analysed elements. This metho

12、d is only possible with good beam-current stability and a separate measurement of at least one reference specimen and it requires very accurate analysis of the other elements in the specimen.Annex D summarizes the problems of light element analysis, additional to those that exist for quantitative an

13、alysis of the heavier elements. If both EDS and wavelength spectrometry (WDS) are available, then WDS can be used to overcome the problems of peak overlap that occur with EDS at low energies. However, many of the other issues are common to both techniques.2 Normative referencesThe following referenc

14、ed documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 14594, Microbeam analysis Electron probe microanalysis Guidelines fo

15、r the determination of experimental parameters for wavelength dispersive spectroscopyISO 15632:2002, Microbeam analysis Instrumental specification for energy dispersive Xray spectrometers with semiconductor detectors ISO 2011 All rights reserved 1BS ISO 22309:2011ISO 16700, Microbeam analysis Scanni

16、ng electron microscopy Guidelines for calibrating image magnificationISO/IEC 17025:2005, General requirements for the competence of testing and calibration laboratories3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1absorption correctionmatrix c

17、orrection arising from the loss of X-ray intensity from an element due to photoelectric absorption by all elements within the specimen while passing through it to the detector3.2accuracycloseness of agreement between the “true” value and the measured value3.3accelerating voltagepotential difference

18、applied between the filament and anode in order to accelerate the electrons emitted from the sourceNOTE Accelerating voltage is expressed in kilovolts.3.4atomic number correctionmatrix correction which modifies intensity from each element in the specimen and standards to take account of electron bac

19、kscattering and stopping power, the magnitudes of which are influenced by all the elements in the analysed volume3.5beam currentelectron current contained within the beamNOTE Beam current is expressed in nanoamperes.3.6beam stabilityextent to which beam current varies during the course of an analysi

20、sNOTE Beam stability is expressed in percent per hour.3.7bremsstrahlungbackground continuum of X-rays generated by the deceleration of electrons within the specimen3.8certified reference materialCRMreference material, one or more of whose property values are certified by a technically valid procedur

21、e, accompanied by or traceable to a certificate or other documentation which is issued by a certifying body3.9characteristic X-rayphoton of electromagnetic radiation created by the relaxation of an excited atomic state caused by inner shell ionization following inelastic scattering of an energetic e

22、lectron, or by absorption of an X-ray photonISO 22309:2011(E)2 ISO 2011 All rights reservedBS ISO 22309:20113.10dead timetime that the system is unavailable to record a photon measurement because it is busy processing a previous eventNOTE This is frequently expressed as a percentage of the total tim

23、e (see also live time).3.11energy-dispersive spectrometryEDSform of X-ray spectrometry in which the energy of individual photons are measured and used to build up a digital histogram representing the distribution of X-rays with energy3.12electron probe microanalysisa technique of spatially resolved

24、elemental analysis based on electron-excited X-ray spectrometry with a focused electron probe and an interaction/excitation volume with micrometre to sub-micrometre dimensions3.13escape peakspeaks that occur as a result of loss of incident photon energy by fluorescence of the material of the detecto

25、rNOTE 1 These occur at an energy equal to that of the incident characteristic peak minus the energy of the X-ray line(s) emitted by the element(s) in the detector (1,734 keV for silicon).NOTE 2 They cannot occur below the critical excitation potential of the detector material, e.g. Si K escape does

26、not occur for energies below 1,838 keV.3.14fluorescencephotoelectric absorption of any X-ray radiation (characteristic or bremsstrahlung) by an atom which results in an excited atomic state which will de-excite with electron shell transitions and subsequent emission of an Auger electron or the chara

27、cteristic X-ray of the absorbing atom3.15fluorescence correctionmatrix correction which modifies the intensity from each element in the specimen and standards to take account of excess X-rays generated from element “A” due to the absorption of characteristic X-rays from element “B” whose energy exce

28、eds the critical (ionization) energy of “A”3.16full width at half maximumFWHMmeasure of the width of an X-ray peak in which the background is first removed to reveal the complete peak profileNOTE FWHM is determined by measuring the width at half the maximum height.3.17incident beam energyenergy gain

29、ed by the beam as a result of the potential applied between the filament and anode3.18k-rationet peak intensity (after background subtraction) for an element found in the specimen, divided by the intensity, recorded or calculated, of the corresponding peak in the spectra of a reference materialISO 2

30、2309:2011(E) ISO 2011 All rights reserved 3BS ISO 22309:20113.19live timetime the pulse measurement circuitry is available for the detection of X-ray photonsSee also dead time (3.10).NOTE 1 Live time is expressed in seconds (s).NOTE 2 Live time = real time for analysis dead time. Real time is the ti

31、me that would be measured with a conventional clock. For an X-ray acquisition, the real time always exceeds the live time.3.20overvoltage ratioratio of the incident beam energy to the critical excitation energy for a particular shell and sub-shell (K, LI, LII, etc.) from which the characteristic X-r

32、ay is emitted3.21peak intensitytotal number of X-rays (counts) under the profile of a characteristic X-ray peak after background subtractionNOTE This is sometimes referred to as the peak integral.3.22peak profiledetailed shape of a characteristic peak which depends on the relative intensities and en

33、ergies of the individual X-ray emissions that are unresolved by the energy-dispersive spectrometer3.23precisioncloseness of agreement between the results obtained by applying the experimental procedure several times under prescribed conditions3.24quantitative EDSprocedure leading to the assignment o

34、f numerical values or expressions to represent the concentrations of elements measured within the analysis volume3.25reference materialRMmaterial or substance, one or more properties of which are sufficiently well established to be used for the calibration of an apparatus, the assessment of a method

35、, or for assigning values to materialsNOTE A reference material is said to be homogeneous with respect to a specified property if the property value, as determined by tests on specimens of specified size, is found to lie within the specified uncertainty limits, the specimens being taken either from

36、a single or different supply unit.3.26repeatabilitycloseness of agreement between results of successive measurements of the same quantity carried out by the same method, by the same observer, with the same measuring instruments, in the same laboratory, at quite short intervals of time3.27reproducibi

37、litycloseness of agreement between the result of measurements of the same quantity, where the individual measurements are made by different methods, with different measuring instruments, by different observers, in different laboratories, after intervals of time that are quite long compared with the

38、duration of a single measurement, under different normal conditions of use of the instruments employedISO 22309:2011(E)4 ISO 2011 All rights reservedBS ISO 22309:20113.28resolutionenergy width of a peak measured by an energy-dispersive spectrometer and expressed as the peak width at half the maximum

39、 peak intensityNOTE This is usually expressed as the value for Mn K (5,894 keV), although peaks from other suitable elements can be used.3.29resolutionspatial spatial specificity of microanalysisNOTE This is usually expressed in terms of a linear or volumetric measure of the region of the specimen t

40、hat is sampled by the measured characteristic radiation.3.30standardless analysisprocedure for quantitative X-ray microanalysis in which the reference peak intensity in the k-value expression (unknown/reference) is supplied from purely physical calculations or from stored data from a suite of refere

41、nce materials, adjustments being made to match analysis conditions and augment incomplete reference data3.31sum peaksartefact peaks that occur as a result of pulse co-incidence effects that occur within the pulse pair resolution of the pile-up inspection circuitryNOTE These peaks appear at energies

42、corresponding to the sum of those energies of the two photons that arrive simultaneously at the detector.3.32traceabilityability to trace the history, application or location of an entity by means of recorded identifications3.33uncertaintythat part of the expression of the result of a measurement th

43、at states the range of values within which the “true” value is estimated to lie for a stated probability3.34validationconfirmation by examination and provision of objective evidence that the particular requirements for a specific intended use are fulfilled3.35X-ray absorptionattenuation of X-rays pa

44、ssing through matter, arising primarily from photoelectric absorption for X-ray energies and ranges appropriate to EPMA/EDS and SEM/EDS4 Specimen preparation4.1 Material for analysis shall be stable under variable pressure conditions and the electron beam. As-received specimens can be examined after

45、 simple cleaning, but surface inhomogeneity or topography will adversely affect the quality of the quantitative analysis.4.2 For reliable quantitative analysis, the specimen shall present a flat, smooth surface normal to the electron beam. This requirement is usually met by the application of conven

46、tional metallographic or petrographic techniques. The area for analysis should be homogeneous over a region, typically a few micrometres in diameter, around the electron beam.ISO 22309:2011(E) ISO 2011 All rights reserved 5BS ISO 22309:20114.3 Solid specimens can be reduced to an appropriate size, m

47、aking sure they undergo no transformation during the process. Prior to examination in the as-received condition, all surface debris should be removed using appropriate techniques, such as ultrasonic cleaning.4.4 Specimens for sectioning should be embedded, where possible, in a conducting medium prio

48、r to metallographic or petrographic polishing using standard procedures. The medium shall be chosen with care, to avoid the possibility of the conducting component becoming smeared onto the specimen surface and being mistaken for a component of the specimen by effectively altering the composition of

49、 the analysed volume.NOTE 1 Polishing may be carried through to 1/4 m grade diamond, provided this can be done without introducing relief effects. Complete removal of all scratches is not essential, provided areas for analysis are clean and relief-free.Damage to the specimen during preparation should be avoided. Potential damage mechanisms include:a) the effects of lubricant;b) the removal of second phases (precipitates);c) differential polishing of phases with different hardness, thus introducing relief to the surface;d) strai