ISO 25498 2025.docx

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1、InternationalStandardISO25498Thirdedition2025-05MicrobeamanalysisAnalyticalelectronmicroscopySelectedareaelectrondiffractionanalysisusingatransmissionelectronmicroscopeAnalyseparmicrofaisceauxMicroscopieelectroniqueanalytiqueAnalysepardiffractionparselectiond,aireaumoyend,unmicroscopeelectroniqueent

2、ransmissionReferencenumberISO25498:2025(en)COPYRIGHTPROTECTEDDOCUMENTISO2025Allrightsreserved.Unlessotherwisespecified,orrequiredinthecontextofitsimplementation,nopartofthispublicationmaybereproducedorutilizedotherwiseinanyformorbyanymeans,electronicormechanical,includingphotocopying,orpostingonthei

3、nternetoranintranet,withoutpriorwrittenpermission.PermissioncanberequestedfromeitherISOattheaddressbeloworISO,smemberbodyinthecountryoftherequester.ISOcopyrightofficeCP401Ch.deBlandonnet8CH-1214Vernier,GenevaPhone:+4122749Ol11Email:copyrightiso.orgWebsite:www.iso.orgPublishedinSwitzerlandContentsPag

4、eForewordivIntroductionv1 Scope12 Normativereferences13 Terms,definitionsandabbreviations13.1 Termsanddefinitions13.2 Abbreviatedtermsandsymbols34 Principle34.1 General34.2 Spotdiffractionpattern44.3 Kikuchipattern64.4 Diffractionpatternofpolycrystallinespecimen75 Referencematerials86 Apparatus86.1

5、Transmissionelectronmicroscope(TEM)86.2 RecordingofSAEDpatternsandimages87 Preparationofspecimens98 Procedure98.1 Instrumentpreparation98.2 ProcedureforacquiringSAEDpatternsfromasinglecrystal108.3 Determinationofdiffractionconstant,L129 MeasurementandsolutionoftheSAEDpatterns149.1 Selectionofthebasi

6、cparallelogram149.2 Indexingdiffractionspots1510 180oambiguity1611 Uncertaintyestimation1611.1 General1611.2 Uncertaintyincameraconstant1711.3 Calibrationwithareferencematerial1711.4 Uncertaintyind-spacingvalues18Annex A (informative)Interplanarspacingsofreferences20Annex B (informative)Spotdiffract

7、ionpatternsofsinglecrystalsforBCC1FCCandHCPstructure21Bibliography42ForewordISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISOmemberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnicalcommittees.Eachmemberbodyinte

8、restedinasubjectforwhichatechnicalcommitteehasbeenestablishedhastherighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,inliaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnicalCommission(IEC)onallmattersofelectrotechn

9、icalstandardization.TheproceduresusedtodevelopthisdocumentandthoseintendedforitsfurthermaintenancearedescribedintheISO/IECDirectives,Part1.Inparticular,thedifferentapprovalcriterianeededforthedifferenttypesofISOdocumentshouldbenoted.ThisdocumentwasdraftedinaccordancewiththeeditorialrulesoftheISO/IEC

10、Directives,Part2(seewww.iso.org/directives).ISOdrawsattentiontothepossibilitythattheimplementationofthisdocumentmayinvolvetheuseof（八）patent(三).ISOtakesnopositionconcerningtheevidence,validityorapplicabilityofanyclaimedpatentrightsinrespectthereof.Asofthedateofpublicationofthisdocument,ISOhadnotrecei

11、vednoticeof（八）patent(三)whichmayberequiredtoimplementthisdocument.However,implementersarecautionedthatthismaynotrepresentthelatestinformation,whichmaybeobtainedfromthepatentdatabaseavailableatwww.iso.org/patents.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights.Anytradenameusedinthis

12、documentisinformationgivenfortheconvenienceofusersanddoesnotconstituteanendorsement.Foranexplanationofthevoluntarynatureofstandards,themeaningofISOspecifictermsandexpressionsrelatedtoconformityassessment,aswellasinformationaboutISOsadherencetotheWorldTradeOrganization(WTO)principlesintheTechnicalBar

13、rierstoTrade(TBT),SeeWWW.isoQrgisoforeword.htmLThisdocumentwaspreparedbyTechnicalCommitteeISO/TC202,Microbeamanalysis,SubcommitteeSC3,Analyticalelectronmicroscopy.Thisthirdeditioncancelsandreplacesthesecondedition(ISO25498:2018),whichhasbeentechnicallyrevised.Themainchangesareasfollows:一Scopehasbeen

14、revised;一ISO/IEC17025hasbeenmovedfromnormativereferencestobibliography;一FigUre1hasbeenreplaced;一Subclause6.3hasbeendeleted;一Subclause8.3.6hasbeendeleted,thecontentof8.3.6hasbeenmovedto8.3.2;一SUbClaUSe925hasbeenaddedandthefollowingsubclausehasbeenrenumbered;一CIaUSeIlhasbeenrevised,11.1,11.2,11.3andIl

15、4havebeenadded;一SUbClaUSeSB41andB42havebeenadded;一BibliographyhasbeenupdatedandISO/IECGuide98-3(GUM:1995)hasbeenadded.Anyfeedbackorquestionsonthisdocumentshouldbedirectedtotheusersnationalstandardsbody.Acompletelistingofthesebodiescanbefoundatwww.iso.org/membnrs.htmLIntroductionElectrondiffractiont

16、echniquesarewidelyusedintransmissionelectronmicroscopy(TEM)studies.Applicationsincludephaseidentification,determinationofthecrystallographiclatticetypeandlatticeparameters,crystalorientationandtheorientationrelationshipbetweentwophases,phasetransformations,habitplanesanddefects,twinsandinterfaces,as

17、wellasstudiesofpreferredcrystalorientations(texture).Whileseveralcomplementarytechniqueshavebeendeveloped,forexamplemicrodiffraction,nanodiffraction,convergentbeamdiffractionandreflecteddiffraction,theselectedareaelectrondiffraction(SAED)techniqueisthemostfrequentlyemployed.Thistechniqueallowsdirect

18、analysisofsmallareasonthinspecimensfromavarietyofcrystallinesubstances.ItisroutinelyperformedonmostTEMsintheworld.TheSAEDisalsoasupplementarytechniqueforacquisitionofhigh-resolutionimages,microdiffractionorconvergentbeamdiffractionstudies.Theinformationgeneratediswidelyappliedinstudiesforthedevelopm

19、entofnewmaterials,improvingstructureand/orpropertiesofvariousmaterialsaswellasforinspectionandqualitycontrolpurpose.ThebasicprincipleoftheSAEDmethodisdescribedinthisdocument.TheexperimentalprocedurefortheacquirementofSAEDpatterns,indexingofthediffractionpatternsanddeterminationofthediffractionconsta

20、ntarespecified.ISO25498isintendedforuseorreferenceastechnicalregulationfortransmissionelectronmicroscopy.MicrobeamanalysisAnalyticalelectronmicroscopySelectedareaelectrondiffractionanalysisusingatransmissionelectronmicroscope1 ScopeThisdocumentspecifiesthemethodforselectedareaelectrondiffraction(SAE

21、D)analysisusingatransmissionelectronmicroscope(TEM)toanalysethincrystallinespecimens.Thisdocumentappliestotestareasofmicrometresandsub-micrometresinsize.Theminimumdiameteroftheselectedareainaspecimenwhichcanbeanalysedbythismethodisrestrictedbythesphericalaberrationcoefficientoftheobjectivelensofthem

22、icroscopeandapproacheshundredsofnanometresforamodernTEM.Whenthesizeofananalysedspecimenareaissmallerthanthesphericalaberrationcoefficientrestriction,thisdocumentcanalsobeusedfortheanalysisprocedure.However,becauseoftheeffectofsphericalaberrationanddeviationofthespecimenheightposition,someofthediffra

23、ctioninformationinthepatterncanbegeneratedfromoutsideoftheareadefinedbytheselectedareaaperture.Insuchcases,theuseofmicrodiffraction(nano-beamdiffraction)orconvergentbeamdiffraction,whereavailable,canbepreferred.ThisdocumentisapplicabletotheacquisitionofSAEDpatternsfromcrystallinespecimens,indexingth

24、epatternsandcalibrationofthecameraconstant.2 NormativereferencesTherearenonormativereferencesinthisdocument.3 Terms,definitionsandabbreviationsForthepurposesofthisdocument,thefollowingtermsanddefinitionsapply.ISOandIECmaintainterminologydatabasesforuseinstandardizationatthefollowingaddresses:一ISOOnl

25、inebrowsingplatform:availableathttps:WWW.iso.org/obp一IECElectropedia:availableathttps:/WWW.electropedia.org/3.1 Termsanddefinitions3.1.1Millernotationindexingsystemforcrystallographicplanesanddirectionsincrystals,inwhichasetoflatticeplanesordirectionsisdescribedbythreeaxescoordinate3.1.2Miller-Brava

26、isnotationindexingsystemforcrystallographicplanesanddirectionsinhexagonalcrystals,inwhichasetoflatticeplanesordirectionsisdescribedbyfouraxescoordinate3.1.3interplanarspacingdhklperpendiculardistancebetweenconsecutiveplanesofthecrystallographicplaneset(hkl)3.1.4reciprocalvector9hklvectorintherecipro

27、callatticeNote1toentry:Thereciprocalvector,。力士/,isnormaltothecrystallographicplane(hkl)withitsmagnitudeinverselyproportionaltointerplanarspacingdhki(3.1.3).3.1.5RvectorRhklcoordinatevectorfromthedirectbeam,OO0,toadiffractionspot,hkl,inazonediffractionpatternNote1toentry:SeeFigUreL3.1.6cameralengthLe

28、ffectivedistancefromthespecimentothescreenorrecordingdeviceinatransmissionelectronmicroscopeindiffractionmode3.1.7cameraconstantdiffractionconstantLproductofthewavelengthoftheincidentelectronwaveandcameralength(3.1.6)SOURCE:ISO15932:2013,3.7.13.1.8brightfieldimageimageformedusingonlythenon-scattered

29、beam,selectedbyobservationofthebackfocalplaneoftheobjectivelensandusingtheobjectiveaperturetocutoutalldiffractedbeamsSOURCE:ISO15932:2013,5.53.1.9darkfieldimageimageformedbyadiffractedbeamonlybyusingtheobjectiveapertureforselectionorbycollectingthediffractedbeamswithanannulardark-fielddetectorSOURCE

30、ISO15932:2013,5.63.1.10energy-dispersiveX-rayspectrometryEDSanalyticaltechniquewhichenablestheelementalanalysisorchemicalcharacterizationofaspecimenbyanalysingcharacteristicX-rayemittedbythematterinresponsetoelectronirradiationSOURCE:ISO15932:2013,6.63.1.11eucentricpositionspecimenpositionatwhichth

31、eimageexhibitsminimallateralmotionresultingfromspecimentilting3.1.12selectedarea(selector)aperturemoveablediaphragmthatisusedtoselectonlyradiationscatteredfromaspecificareaofthespecimentocontributetotheformationofadiffractionpatternSOURCE:ISO15932:2013,3.2.3.53.1.13BraggangleBanglebetweentheincident

32、beamandtheatomicplanes,atwhichdiffractiontakesplace3.2 AbbreviatedtermsandsymbolsBCCbody-centredcubicstructureFCCface-centredcubicstructureHCPhexagonalclose-packedstructureSAEDselectedareaelectrondiffractionTEMtransmissionelectronmicroscope(hkl)MillerindicesofaspecificsetofcrystallographicplaneshklM

33、illerindiceswhichdenoteafamilyofcrystallographicplanesuvwMillerindicesofaspecificcrystallographicdirectionorazoneaxis(vv)*NotationforasetofplanesinthereciprocallatticeNOTEThenormalofthereciprocalplaneuvw)*isparalleltothecrystallographiczoneaxisuvw4 Principle4.1 GeneralWhenanenergeticelectronbeamisin

34、cidentuponathincrystalspecimeninatransmissionelectronmicroscope,adiffractionpatternwillbeproducedinthebackfocalplaneoftheobjectivelens.Thispatternismagnifiedbytheintermediateandprojectorlenses,thendisplayedonaviewingscreenandrecorded(seeReference3j4,5).ThispatterncanalsobedisplayedonamonitoriftheTEM

35、isequippedwithadigitalcamerasystem.Thegeometricrelationshipoftheparametersforselectedareaelectrondiffraction(SAED)techniquecanbeunderstoodthroughtheEwaldsphereconstruction,whichisillustratedinFigure1.Key1 incidentbeam2 specimen3 directbeam4 diffractedbeam5 Ewaldsphere6 reciprocalvectorghkl7 diffract

36、ionpattern8 RhklVeCtOrListhediffractioncameralength;如isBraggangle;入isthewavelengthoftheincidentelectronbeam.Figure1EwaldsphereconstructionillustratingthediffractiongeometryinTEM4.2SpotdiffractionpatternThediffractionpatternofasinglecrystalappearsasanarrayof“spots”,thebasicunitofwhichischaracterizedb

37、yaparallelogram.AnexampleofthespotdiffractionpatternisshowninFigure2.Eachspotcorrespondstodiffractionfromaspecificsetofcrystallatticeplanesinthespecimen,denotedbyMillerindices(hkl).Thevector,Rhk,isdefinedbythepositionofthediffractedspot,hklfrelativetopositiononthepatterncorrespondingtothedirectbeam,

38、i.e.thecentre-spot,OOO,ofthepattern.Itisparalleltothenormalofthereflectingplane,(hW).ThemagnitudeofRhklisinverselyproportionaltotheInterplanarspacing,djthediffractingplane,(hkl)(seeReferences4to9.Inthecontextofthisdocument,vectorsRhk1l1Rhk2(Rijg)and(P2c11+2c22)1areSimglifiedasRlfR2fR2nlandR1+2respec

39、tively.Theincludedanglebetweenvectors,R1andR2,isdenotedby*.ThebasicparallelogramisdefinedbyRlandR2wheretheyaretheshortestandnextshortestinthepatternrespectivelyandnotalongacommonline.Thespot,h2k212,ispositionedanticlockwisearoundthecentrespotrelativetospot,hkl1.Becausethecentre-spotisoftenverybright

40、itisoftendifficulttodeterminetheexactcentreofthepattern.Therefore,apracticalprocedureistoestablishthemagnitudeofRhkbymeasuringthedistancebetweenthespots,hklandhklonthediffractionpatternanddividingbytwo,i.e.Rhkl=局).OntheexamplepatternshowninFigUre2,themagnitudeofR1,R2and2isobtainedfrom$R1+RD，22+2Jan

41、d2(正+20respectively.KeyR1isthevectorfrom000tospot,h1k1l1,theshortestvectorinthediffractionpatternR2isthevectorfrom000tospot,h2k2l2,thenextshortestvectorNOTEThebasicparallelogramisconstitutedbyR1and4Figure2ExampleofthespotdiffractionpatternfromasinglecrystalTherelationshipbetweentheInterplanarspacing

42、dhkt,andthemagnitudeofRhklforareflectingplane,(hkl),canbeapproximatelyexpressedasshowninFOrmUIa(1)(seeReferences7and8J:L=RhklXdhkl山MRhkIL)2=RhkiXdhkl(1口A)(1)whereisequaltoListhediffractioncameralengthandequaltof0MiMp;wheref0isthefocallength,inmillimetres,oftheobjectivelensinthemicroscope;Miisthemag

43、nificationoftheintermediatelens;MPisthemagnificationoftheprojectorlenses;Listhecameraconstant(ordiffractionconstant)ofthetransmissionelectronmicroscopeoperatingundertheparticularsetofconditions.Thisparametercanbedeterminedfromthediffractionpatternofacrystallinespecimenofknownlatticeparameters(see8.3

44、);isthewavelength,innanometres,oftheincidentelectronbeamwhichisdependentupontheacceleratingvoltageandcanbegivenbyFOnrIUIa(2)(seeReference4J:Mnm)=(2)y(l+0,978810116y)whereVistheacceleratingvoltage,involts,oftheTEM;thefactorinparenthesisistherelativisticcorrection.FormostworkusingaTEM,thevalueofinForm

45、UIa(I)isusuallysmallerthan0,1%and,hence,amoresimplifiedFOmUIa(3)maybeused:Rhkldhkl=i(3)Forthederivationoftheaboveequation,refertothetextbooks(seeReferences4to9.TheuseofFOITnUIa(3)requiresmeasuringthelengthofRhk：Since,asmentionedearlier,thelocationofthepatterncentremaynotbeeasilydetermined;itisrecomm

46、endedthatthedistancemeasurementtaken,2Rhkjbefromthehc1diffractedspottothehsgotonthepattern.Thisisequivalenttoadiametermeasurementontheringpatternfromapolycrystallinespecimen(Section4.4andFigure4).ToobtaintheInterplanarinformation,themeasureddistance,2R或支,ishalvedandFOrmUIa(3)applied.Ifthecameraconst

47、antisknown,theInterplanarspacing,dhki,ofplane,(hkl),canbecalculated.Theincludedanglebetweenanytwovectors,RhIklhandR,canalsobemeasuredonthediffractionpattern.Thisisequaltotheanglebetweenthecorrespondingcrystallographicplanes,(hkl1)and(hk2)Sincediffractiondatafromasinglepatternwillprovideinformationonalimitednumberofthepossiblediffractingplanesinaspecimenarea,itisnecessarytoacquireadditionaldiffractionpatternsfromthesamearea(orfromdifferentgrains/particlesofthesamephase).Thisrequireseitherthetiltingofthespecimenortheavailabilityofdifferentlyorientedgrainsorparticlesofthesam