分析电子显微镜AEM课件

PartIIIAnalyticalElectronMicroscopyinMaterialsScience1.Introduction2.ImagemodeinAEM3.MicroanalysisinAEM3.1X-rayEnergyDispersiveSpectroscopy(EDS)3.2ElectronEnergyLossSpectroscopy(EELS)3.3Microdiffraction3.4Convergentbeamdiffraction

PartIIIAnalyticalElectronM11、Introduction1.Signalsgeneratedintheinteractionbetweentheincidenthighenergyelectronbeamandthethincrystallinespecimen2.Howtoformaprobe3.RelationshipbetweenTEM,SEMandAEM3.1TEMImagemodeDiffractionmode3.2SEMImagemode:SE,BSE,X-RayMappingMicroanalysis:WDS,EDS3.3AEMImagingmode:TEM,STEM,SEM,Mapping(X-Ray+EELS)Diffractionmode:ScanningprobeStationarydiffractionpatternMicroanalysis:EDS,EELS,micro-diffraction,convergentbeamdiffraction

1、Introduction1.Signalsgenera2分析电子显微镜AEMppt课件3分析电子显微镜AEMppt课件4分析电子显微镜AEMppt课件5分析电子显微镜AEMppt课件6Howtoformaprobe?Howtoformaprobe?7分析电子显微镜AEMppt课件8分析电子显微镜AEMppt课件9分析电子显微镜AEMppt课件10DetectorsneededforanAEMDetectorsneededforanAEM11分析电子显微镜AEMppt课件12分析电子显微镜AEMppt课件13分析电子显微镜AEMppt课件14分析电子显微镜AEMppt课件15分析电子显微镜AEMppt课件16分析电子显微镜AEMppt课件173.RelationshipbetweenTEM,SEMandAEM

3.1TEMImagemodeDiffractionmode3.2SEMImagemode:SE,BSE,X-RayMappingMicroanalysis:WDS,EDS3.3AEMImagingmode:TEM,STEM,SEM,Mapping(X-Ray+EELS)Diffractionmode:ScanningprobeStationarydiffractionpatternMicroanalysis:EDS,EELS,micro-diffraction,convergentbeamdiffraction3.RelationshipbetweenTEM,SE18分析电子显微镜AEMppt课件193.2SEMImagemode:SE,BSE,X-RayMappingMicroanalysis:WDS,EDS3.2SEM20分析电子显微镜AEMppt课件21SEM二次电子像的衬度——拓扑衬度SEM二次电子像的衬度——拓扑衬度22分析电子显微镜AEMppt课件23分析电子显微镜AEMppt课件24分析电子显微镜AEMppt课件25分析电子显微镜AEMppt课件26分析电子显微镜AEMppt课件27分析电子显微镜AEMppt课件283.3AEMImagingmode:TEM,STEM,SEM,Mapping(X-Ray+EELS)Diffractionmode:ScanningprobeStationarydiffractionpatternMicroanalysis:EDS,EELS,Micro-diffraction,Convergentbeamdiffraction3.3AEM29分析电子显微镜AEMppt课件30分析电子显微镜AEMppt课件31分析电子显微镜AEMppt课件321.BFdetector

ItisplacedatthesamesiteastheapertureinBF-TEManddetectstheintensityinthedirectbeamfromapointonthespecimen.2.ADFdetector

Theannulardarkfield(ADF)detectorisadiskwithaholeinitscenterwheretheBFdetectorisinstalled.TheADFdetectorusesscatteredelectronsforimageformation,similartotheDFmodeinTEM.ThemeasuredcontrastmainlyresultsfromelectronsdiffractedincrystallineareasbutissuperimposedbyincoherentRutherfordscattering.3.HAADFdetector

Thehigh-angleannulardarkfielddetectorisalsoadiskwithahole,butthediskdiameterandtheholearemuchlargerthanintheADFdetector.Thus,itdetectselectronsthatarescatteredtohigheranglesandalmostonlyincoherentRutherfordscatteringcontributestotheimage.Thereby,Zcontrastisachieved.1.BFdetector

Itisplacedat33分析电子显微镜AEMppt课件34分析电子显微镜AEMppt课件35分析电子显微镜AEMppt课件362、ImaginginAEM2.1.TEM2.2.STEM-Scanningtransmissionelectronmicroscopy2.3.STEM/SEMimaging2.4.Signalmixing-Hybridimaging2.5.X-RayandEELSmapping

2、ImaginginAEM2.1.TEM37分析电子显微镜AEMppt课件38分析电子显微镜AEMppt课件39分析电子显微镜AEMppt课件40分析电子显微镜AEMppt课件41分析电子显微镜AEMppt课件42分析电子显微镜AEMppt课件43分析电子显微镜AEMppt课件44分析电子显微镜AEMppt课件45分析电子显微镜AEMppt课件46分析电子显微镜AEMppt课件47分析电子显微镜AEMppt课件48分析电子显微镜AEMppt课件49分析电子显微镜AEMppt课件50分析电子显微镜AEMppt课件51分析电子显微镜AEMppt课件52STEMimagesofPtparticlesinSiO2nanotubes

IntheBF-STEMimage,thecontrastissimilartothatinBF-TEMimages:Ptparticlesappearwithdarkcontrastsincetheyarecrystallineandtheheaviestscatterersinthissystem.IntheADF-STEMimage,thePtparticlesappearwithbrightcontrastbecauseofdiffractionandincoherentscattering(cf.,DF-TEMimages).IntheHAADF-STEMimage,onlytheincoherentlyscatteredelectronscontributetotheimage,whichnonethelessappearstobeverysimilartotheADF-image.STEMimagesofPtparticlesin53HAADF-STEMimageofAu/PtparticlesonSilica

Inthehigh-angleannulardarkfield(Zcontrast)image,themetalparticles,whichhavehighatomicnumbersZcomparedtotheSiO2matrix,areimagedasbrightdots.Thus,thismethodisavaluabletooltoinvestigatecatalystsandtodeterminethesizesofmetalparticlesandthecorrespondingsizedistribution.HAADF-STEMimageofAu/Ptpart54High-ResolutionHAADF-STEM

Fourier-filteredHAADF-STEMimageofNb4W13O47oxidizedat1000°C.ProjectionalongtheshortaxisThisHAADF-STEMimageshowsWO3segregationsinamatrixofaTTB-typeNb-Woxide.Thepositionsofthemetalatomcolumnsappearwithbrightcontrast(c.f.,HRTEMimageofNb4W13O47

High-ResolutionHAADF-STEMFou553、MicroanalysisinAEM3.1X-Rayquantitativemicroanalysis3.1.1X-RaysignalgenerationinTEMthinfoilspecimens3.2.2Identificationandeliminationofspurioussignals3.2.3OptimizationoftheAEMformicroanalysis3.2.4X-Raymicroanalysis3.2.5Microanalysislimit3.2EELS-ElectronEnergyLossSpectroscopy3.2.1energylossprocessinthinfoilTEMspecimens3.2.2Wheretofindtheenergylosselectrons?3.2.3Electronenergylossspectrometer3.2.4ComparisonofthesignalgeneratingprocessforEDSandEELS3.2.5Theenergylossspectrum3.2.6EELSMicroanalysisandthelimitofanalysis3.2.7Conclusionremarks3.3ComparisonbetweenEDSandEELS

3、MicroanalysisinAEM3.1X-Ra56分析电子显微镜AEMppt课件57X-RaysignalgenerationinTEMthinfoilspecimensFluorescenceyield(w):w=0forZ～5(Boronkshellionization)Z～27(CobaltLshell)Z～57(lathanlumMshell)X-RaysignalgenerationinTEM58分析电子显微镜AEMppt课件59分析电子显微镜AEMppt课件60分析电子显微镜AEMppt课件61分析电子显微镜AEMppt课件62分析电子显微镜AEMppt课件63分析电子显微镜AEMppt课件64分析电子显微镜AEMppt课件653.2.3OptimizationoftheAEMformicroanalysis3.2.4X-Raymicroanalysis3.2.3OptimizationoftheAEM66分析电子显微镜AEMppt课件67分析电子显微镜AEMppt课件68CliffandLorimer:CA+CB=100%CliffandLorimer:CA+CB=100%69分析电子显微镜AEMppt课件70LimitformicroanalysisbyEDS1.Absoluteaccuracy

2Minimumdetectablemass:MDM

10-20g3Minimummassfraction:MMF0.1wt%4Spatialresolution:10～20nm5LowZlimit6Practicallimitations:(1)contamination(2)Embeddedparticales

LimitformicroanalysisbyEDS71分析电子显微镜AEMppt课件72分析电子显微镜AEMppt课件73分析电子显微镜AEMppt课件74分析电子显微镜AEMppt课件75分析电子显微镜AEMppt课件763.2EELS-ElectronEnergyLossSpectroscopy3.2.1energylossprocessinthinfoilTEMspecimens3.2.2Wheretofindtheenergylosselectrons?3.2.3Electronenergylossspectrometer3.2.4ComparisonofthesignalgeneratingprocessforEDSandEELS3.2.5Theenergylossspectrum3.2.6EELSMicroanalysisandthelimitofanalysis3.2.7Conclusionremarks

3.2EELS-ElectronEnergyLos77分析电子显微镜AEMppt课件783.2.2Wheretofindtheenergylosselectrons?3.2.2Wheretofindtheenergy79分析电子显微镜AEMppt课件80分析电子显微镜AEMppt课件813.3.3EELSSpectrometer3.3.3EELSSpectrometer823.2.4ComparisonofthesignalgeneratingandcollectionprocessforEDSandEELS

1.SignalgenerationEDS-secondaryeventHighenergyincidentelectronsexcitationofatomscharacteristicX-raysorAugerelectronsEELS-primaryevent2.CollectionefficiencyEDS-verylow!!X-Raygeneration:forcarbon:1inevery400k-shellionizationforNa,1in40Collectionefficiency:WDS:10-3-10-4EDS:～10-2Goldlayer(20nm):onlyallow67%betransmitted!TheDeadlayerbelowthegoldlayer:37%ofthe67%betransmitted!EELS:veryhigh!!75%oftheenergylosselectronswithacollectionangleof10mrad100%whencollectionangleis30mrad3.2.4Comparisonofthesignal83分析电子显微镜AEMppt课件84

3.2.5Theenergylossspectrum(1)Thezerolosspeak(2)Thelowlossregionofthespectrum

DE<50eVplasmonpeaks(3)Highenergyregionofthespectrum

DE>=50eVenergylosspeak-ionizationedgespre-edgeandpost-edgestructure3.2.5Theenergylossspectru85分析电子显微镜AEMppt课件86分析电子显微镜AEMppt课件87分析电子显微镜AEMppt课件88分析电子显微镜AEMppt课件89分析电子显微镜AEMppt课件90分析电子显微镜AEMppt课件91Microanalysisusingionizationpeaks(edges)Microanalysisusingionization92分析电子显微镜AEMppt课件93分析电子显微镜AEMppt课件94分析电子显微镜AEMppt课件95分析电子显微镜AEMppt课件96分析电子显微镜AEMppt课件97分析电子显微镜AEMppt课件98分析电子显微镜AEMppt课件99分析电子显微镜AEMppt课件1003.2.5ThelimitationsinEELSanalysis1.DetectionlimitsMDM:In500ÅFefoil,103atomsforLiandAl3x104atomsforO(k-edge)MDF:Cin300Åsteel:3at%(100atoms)Oin600Åsteel:6at%2.Specimenthickness3.Spatialresolution3.2.5ThelimitationsinEELS101分析电子显微镜AEMppt课件102分析电子显微镜AEMppt课件103分析电子显微镜AEMppt课件104分析电子显微镜AEMppt课件105分析电子显微镜AEMppt课件106分析电子显微镜AEMppt课件107分析电子显微镜AEMppt课件108分析电子显微镜AEMppt课件109分析电子显微镜AEMppt课件110PhaseidentificationPhaseidentification111分析电子显微镜AEMppt课件112分析电子显微镜AEMppt课件113分析电子显微镜AEMppt课件1144、MicroDiffraction4.1LimitoftheSelectedareaelectrondiffraction(SAD)4.2Microdiffraction4.2.1theRickemethod4.2.2convergentbeammicrodiffraction

4、MicroDiffraction4.1Limito1154.1LimitoftheSelectedareaelectrondiffraction(SAD)4.1LimitoftheSelectedarea116分析电子显微镜AEMppt课件117分析电子显微镜AEMppt课件118分析电子显微镜AEMppt课件119分析电子显微镜AEMppt课件120分析电子显微镜AEMppt课件121分析电子显微镜AEMppt课件1225、Convergentbeamdiffraction5.1Terminology5.2HowtogetaCBDP5.3ZOLZ-theZeroOrderLaueZone5.4ThicknessMeasurementbyCBDP5.5HOLZ-HigherOrderLaueZone5.6HOLZLines-HigherOrderLaueZoneLines5.7ZAPS-thezoneAxisPatters5.8Acquiring3-Dsymmetryinformation5.9Phaseidentification5.10summary

5、Convergentbeamdiffraction5123分析电子显微镜AEMppt课件1245.1TerminologyZOLZ-ZeroOrderLaueZoneHOLZ-HigherOrderLaueZoneFOLZ-FirstOrderLaueZoneSOLZ-SecondOrderLaueZoneKikuchiLinesHOLZLinesDynamicalEffectK-MPatternKosselPattern5.1TerminologyZOLZ-ZeroOrd125分析电子显微镜AEMppt课件126分析电子显微镜AEMppt课件127分析电子显微镜AEMppt课件1285.2HowtogetaCBDP5.2HowtogetaCBDP129分析电子显微镜AEMppt课件130分析电子显微镜AEMppt课件131分析电子显微镜AEMppt课件1325.3ZOLZ-theZeroOrderLaueZone5.3ZOLZ-theZeroOrderLaue133分析电子显微镜AEMppt课件134分析电子显微镜AEMppt课件135分析电子显微镜AEMppt课件1365.4ThicknessMeasurementbyCBDP5.4ThicknessMeasurementbyC137分析电子显微镜AEMppt课件138分析电子显微镜AEMppt课件1395.5HOLZ-HigherOrderLaueZone5.5.1HigherorderLauezone5.5.2Determinationofinterplanar

spacingsparalleltotheelectronbeamdirection5.5.3IndexingoftheHOLZmaximahu+kv+lw=1forFOLZmaximahu+kv+lw=2forSOLZmaxima5.5HOLZ-HigherOrderLaueZ140分析电子显微镜AEMppt课件141分析电子显微镜AEMppt课件142分析电子显微镜AEMppt课件143Forfcc:WhenU+V+WoddWh