TEM制样浅谈PPT课件.ppt

Learningoftransmissionelectronmicroscopictechnology Sharingmyexperience TEM制样浅谈 Contents Contents Preparation Preparationofspecimen1 howtoprepare Methods equipments andpeople Preparationinthoughts1 whatdoyouwant 2 Howtogetit 3 whatcanwegain PreparationofTEMspecimen 1 Chemicalpolishing 化学减薄 双喷减薄 样品基本要求 表面 新鲜 清洁 无氧化层 冲样后应去除边缘毛刺 关键参数 腐蚀液配方 双喷电压 温度 合格样品 表面非常光亮 穿孔位于样品中心 孔小而粗糙 PreparationofTEMspecimen 2 Ionpolishing 离子减薄 关键参数 凹坑样品好坏 离子束电压 功率及入射角度 合格样品 表面光亮 穿孔位于样品中心 孔小而粗糙 一旦穿孔立即停止减薄过程 PreparationofTEMspecimen 3 Replicatechniques 复型技术 PreparationofTEMspecimen 3 Powders 粉末样品 直接观察 将粉末放入无水乙醇溶液中 采用超声波震荡分散均匀后 滴在微栅上 干燥后直接进行透射观察 适合纳米级粉末分析 树脂包埋 包埋剂要求 高强度 高温稳定性 与多种化学试剂不发生反应 常用包埋剂 G1 G2 610等 该种方法还可用于薄膜 涂层样品制备 Preparationinthoughts ReferencesResultsandresearchmethods SAED EDS ofothers PredictionThemicrostructures phases orthestructureconstantsofdifferentcrystals etc DeviceparametersTheresolutionofTEM EDS etc FEITecnaiG220 Pointresolution 0 234nmacceleratingvoltage 200KVSingleanddoubletiltspecimenholders 45 40 OxfordinstrumentsEDSdetector Contents OperationofTEM MethodBright fieldimage a Microstructuresormorphologyanalysis b Magnificationrange 21x 700kxinTEMmode FEIG20 c Comparableimages TEMimagesof2E12alloyinT4state OperationofTEM MethodDark fieldimage a advantages effectivetechniqueforusesinvolvingunstainedsamplesb disadvantages lowlightlevelsimage c specimenrequirement thickness DFI OperationofTEM TheimagesofBFandDF SAED OperationofTEM MethodSelectedareaelectrondiffraction SAED a thecharacteristicsofdiffractionpatternsinlowindexdirectionsb thesizeofconstituencyaperture 选区光阑 Ag 100 Ag 110 Ag 112 Ag 111 2020 3 19 15 OperationofTEM MethodEDS minsizeofelectronbeam 20nm FEIG20 80nm a Takenotesb Correspondingbright fieldimage Efficiency Efficiency Money Time Contents AnalysisofTEMresults Thecharacterizationofinterfacestructurebetweendifferentphasesa thedeterminationoforientationrelationshipsb theatomicstructureandchemicalcompositionofinterface Grainboundary MartensiteinTialloy Variouskindsofinterfacestructures Determinationoforientationrelationships FortheelongatedoctahedralshapedSnO2precipitate OR FortheplateshapedSnO2precipitate OR Determinationoforientationrelationships Determinationoforientationrelationships AdirectioninmatrixphasecanbetransformedtothecorrespondingparalleldirectioninprecipitatephasebyamatrixB andaplaneinmatrixcanbetransformedtothecorrespondingparallelplaneinprecipitatephasebyamatrixA ForaORbetweenmatrixandprecipitatephase wecanproposeasfollows Determinationoforientationrelationships Determinationoforientationrelationships Foraplane hkl wecanexpressinreciprocalvector Thenormaldirection uvw canbeexpressedinrealvector Foranycrystal Determinationoforientationrelationships Determinationoforientationrelationships OR OR ORIandIIaretheessentiallysame AnotherwaytodeterminetheORsbetweenmatrixandprecipitatesisthestereographicprojectionsmethod Determinationoforientationrelationships Summary Inawords thisissom