x-射线光电子能谱.ppt

x-射线光电子能谱.ppt

ID:62011061

大小:1.44 MB

页数:19页

时间:2021-04-12

x-射线光电子能谱.ppt_第1页
x-射线光电子能谱.ppt_第2页
x-射线光电子能谱.ppt_第3页
x-射线光电子能谱.ppt_第4页
x-射线光电子能谱.ppt_第5页
资源描述:

《x-射线光电子能谱.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库

1、NanoscopicCharacterizationMethods: X-rayPhotoelectronSpectroscopyXPS:SystemCharacteristicsIntroductionBackgroundTheoryInstrumentationSystemPerformanceSensitivityResolutionLimitationsCurrentApplicationsFutureImprovementsXPS:IntroductionCharacterizationofsurfacecomposition/molecularfunctionality

2、X-radiationofsurfacesejectsphotoelectronsElectronsanalyzedbydetector,energydeterminedOrbitalspossesscharacteristiceVassignments;correlatedtodetermineelementalcomposition???XPS:TheoryBasedonEinstein’sRelationship:E=photonenergy,h=Plancksconstant(6.62x10-34Js),c=speedoflight,andv=frequency(Hz)of

3、theradiation.XPS:TheoryInitialConditionsA+hv=A++e-ConservationofEnergyE(A)+hv=E(A+)+E(e-)RearrangeEq.,obtainKEKE=hv-E(A+)+E(A)FinalEquationKE=hv–BE,*WhereBE=energydifferencebetweenionizedandgroundstateKE=hv–BE-Φ,whenworkfunctionincludedXPS:TheoryOtherConditionstoConsider:DoubletStatesSecondary

4、ReactionsDoubletStates(1s)2(2s)2(2p)6(3s)2(3p)6(3d)10....InstrumentalComponentsX-RaySource:TwinAnodeMg/AlSourceMonochromaticSourceAnalyzer:ConcentricHemisphericalAnalyzer(CHA)Detector:ChanneltronElectronMultiplierVacuumSystemInstrumentalComponentsX-RaySource:TwinAnodeMg/AlSourceUseselectricfil

5、amenttoproduceelectronsAcceleratetowardsanodeandgeneratex-raysSwitchbetweenanodestochoosephotonenergySimple,inexpensiveHighfluxofx-rayphotonsPoorresolutionMonochromaticSourceUsesdiffractionthroughquartzcrystaltoselectx-rayphotonsofcertainwavelengthsImprovesresolutionInstrumentalComponentsAnaly

6、zer:ConcentricHemisphericalAnalyzer(CHA):2concentrichemispheresofdifferentradiiVoltagebiasapplied–varytoscanenergyspectrumFilterelectronsbyselectingelectronsofcertainkineticenergyInstrumentalComponentsDetector:ChanneltronelectronmultiplierMeasuresnumberofelectronsofspecificbindingenergiesLeads

7、ilicateglassConductiveandproducessecondaryelectronemissionOutputplacedathighVaccelerateelectronsSensitivityPhotoelectronInelasticMeanFreePath(IMFP)X-rayradiationse-e-X-raypenetrationdepthIMFPX-rayPenetrationDepthProbabilityofEscapingPh

当前文档最多预览五页,下载文档查看全文

此文档下载收益归作者所有

当前文档最多预览五页,下载文档查看全文
温馨提示:
1. 部分包含数学公式或PPT动画的文件,查看预览时可能会显示错乱或异常,文件下载后无此问题,请放心下载。
2. 本文档由用户上传,版权归属用户,天天文库负责整理代发布。如果您对本文档版权有争议请及时联系客服。
3. 下载前请仔细阅读文档内容,确认文档内容符合您的需求后进行下载,若出现内容与标题不符可向本站投诉处理。
4. 下载文档时可能由于网络波动等原因无法下载或下载错误,付费完成后未能成功下载的用户请联系客服处理。