Diffraction Methods & Electron Microscopy Lecture 2
FYS 4340/FYS 9340Diffraction Methods& Electron MicroscopyLecture 2Sandeep GorantlaFYS 4340/9340 course – Autumn 20161
Transmission ElectronMicroscopyIntroduction and BasicsPart- 1Sandeep GorantlaFYS 4340/9340 course – Autumn 20162
Learning more about TEM!Courtesy: WWW.amazon.comFYS 4340/9340 course – Autumn 20163
Learning more about TEM!http://www.matter.org.uk/tem/4
Learning more about TEM!5
Why learn aboutTransmission Electron Microscopy (TEM)?FYS 4340/9340 course – Autumn 20166
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Role of TEM in Materials Science Research and DevelopmentSolving Materials Science problems/mysteriesby probing analytically and understandingstructure-property relationships atatomic scale levelMaterials Science ParadigmCourtesy: www.wikipedia.comFYS 4340/9340 course – Autumn 20168
Allotropes of carbongraphenegraphitenanotubefullerene(Courtesy: The Royal Swedish Academy of Sciences)FYS 4340/9340 course – Autumn 20169
10Courtesy: www.extremetech.com
Courtesy: Knut Urban, Nature Materials 10, 165–166 (2011)11
1D nanomaterials modification in TEM-Irradiation of solids with energetic particles usually leads to damage-However, in the case of carbon nanostructures, electron irradiation was observed to have somebeneficial effects(a) Irradiation – mediated engineering(b) self-assembly or self-organizationCourtesy: Krasheninnikov, A. V. et al., Nature Mater., 6, 723 (2007)FYS 4340/9340 course – Autumn 201612
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Interface: defects on outer-wall of a nanotube and fullereneCourtesy: Gorantla, S. et al., Nanoscale, 2, 2077 (2010)FYS 4340/9340 course – Autumn 201615
Interface: defects on outer-wall of a nanotube and fullereneNanohump formation (Covalent interactions of fullerene fusion)Movie Settings: Frame speed: 0.6 s Total Frames: 48Experimental conditions: Acquisition time: 1 s Time gap betweenindividual frames: 1s - 30s Total time: 14 minsCourtesy: Gorantla, S. et al., Nanoscale, 2, 2077 (2010)FYS 4340/9340 course – Autumn 201616
Interface: defects on the outer-wall of a SWCNT and fullereneFullerene fusion with a nanohump (Covalent interactions of fullerene fusion)Movie Settings: Frame speed: 0.6 s Total Frames: 48Experimental conditions: Acquisition time: 1 s Time gap betweenindividual frames: 1 sCourtesy: Gorantla, S. et al., Nanoscale, 2, 2077 (2010)FYS 4340/9340 course – Autumn 201617
HETEROSOLAR PROJECTThe aim of the workDevelop new solar cell devices base onZnO/Cu2O heterojunctions coupled withconvetional Si based solar cellsProperties determined by the structures, faultsand interfaces.TCOZnOn-type3.4 eVCu2O2.17 eVp-type* Theoretical eficiency 20 %* Highest exp. eficiency 1-4 %SiSub project : (S)TEM to characterize the thin films and their interfaces.18
Cu2O (sputtering, 300nm)Cu2OZnO Single CrystalCu2OCuOZnO?50 nm1 nmZnOFYS 4340/9340 course – Autumn 201619
CuOZnOFYS 4340/9340 course – Autumn 201620
Transmission Electron MicroscopeBrief History21FYS 4340/9340 course – Autumn 2016
Brief History: The first electron microscopeErnst Ruska:Nobel Prize in physics 1986 Knoll and Ruska, first TEM in 1931Idea and first images published in 1932By 1933 they had produced a TEMwith two magnetic lenses which gave12 000 times magnification.Electron Microscope DeutschesMuseum, 1933 model22
Brief History: The state-of-art TEMElectron Microscope DeutschesMuseum, 1933 modelFEI Titan 60-300 TEM, NORTEM facility- UiOInstalled: 201423
Brief History: The state-of-art TEMBIG LEAP: Introduction of Lens Aberration Correctors allowing atomic resolution at low accelerating voltages.Resolution limitYear1940s1950s1960s1970s1980s1990s2000sBefore Cs correctionResolution 10nm 0.5-2nm0.3nm (transmission) 15-20nm (scanning)0.2nm (transmission)7nm (standard scanning)0.15nm (transmission)5nm (scanning at 1kV)0.1nm (transmission)3nm (scanning at 1kV) 0.1 nm (Cs correctors)Typical TEM operating voltagesin Materials Science ResearchCourtesy: als/public/ElecMicr.htm300 kV200 kV80 kV60 kVAfter Cs correctionCore of the M100 galaxy seen throughHubble (source: NASA)FYS 4340/9340 course – Autumn 201624
Transmission Electron MicroscopeFundamentalsFYS 4340/9340 course – Autumn 201625
Electrons interaction with the specimenElectrons have both wave and particle natureTypical specimen thickness 100 nm or lessTypical TEM operating voltagesin Materials Science ResearchCourtesy: D.B. Williams & C.B. Carter, Transmission electron microscopy300 kV200 kV80 kV60 kVFYS 4340/9340 course – Autumn 201626
Electron lensesAny axially symmetrical electric or magnetic field have the propertiesof an ideal lens for paraxial rays of charged particles. ElectrostaticF -eE– Not used as imaging lenses, but are used in modern monochromators ElectroMagnetic F -e(v x B)– Can be made more accurately– Shorter focal lengthCourtesy: c lenses.htmFYS 4340/9340 course – Autumn 201627
TEM Lens Aberrations Spherical aberration coefficientr2ds 0.5MCsα3αr1M: magnificationCs :Spherical aberration coefficientα: angular aperture/angular deviation from optical axisDisk of least confusionSpherical aberrationxy-focusv - ΔvvChromatic aberrationyx-focusAstigmatismFYS 4340/9340 course – Autumn 201628
TEM Lens AberrationsSchematic of spherical aberration correctionCourtesy: Knut W. Urban, Science 321, 506, 2008; CEOS gmbh, Germany; www.globalsino.comFYS 4340/9340 course – Autumn 201629
TEM Lens AberrationsWhy we need an aberration-corrected TEM at 80kV?-Correcting aberrations improves the TEM resolution at 80 kVUncorrected 80 kV 0.3 nm(Courtesy: NASA)Corrected 80 kV 0.14 nm- Improved resolution enables the possibility of imaging carbon nanostructures at atomic levelUncorrected80 kVAberr. corrected80 kVFYS 4340/9340 course – Autumn 201630
Transmission Electron MicroscopeInstrumentation – Part 1FYS 4340/9340 course – Autumn 201631
FEG gunExtraction AnodeGun lensMonochromator ApertureMonochromatorAcceleratorGun Shift coilsC1 aperture/mono energy slitC1 lensC2 lensC2 apertureCondenser alignment coilsC3 lensC3 apertureBeam shift coilsMini condenser lensObjective lens upperSpecimen StageObjective lens upperImage Shift coilsObjective apertureCs CorrectorSA ApertureDiffraction lensIntermediate lensProjector 1 lensProjector 2 lensHAADF detectorViewing ChamberPhosphorous ScreenBF/CCD detectorsEELS prismGIF CCD detectorCourtesy: David Rassouw, CCEM, CanadaFYS 4340/9340 course – Autumn 201632
Electron gunIlluminationsystemSpecimen stageImagingsystemProjection andDetection systemCourtesy: David RassouwFYS 4340/9340 course – Autumn 201633
FEG Electron gun sourceFYS 4340/9340 course – Autumn 201634
Specimen StageFYS 4340/9340 course – Autumn 201635
TEM Specimen HolderFYS 4340/9340 course – Autumn 201636
TEM Specimens Typically 3 mm in diameterCourtesy: http://asummerinscience.blogspot.noFYS 4340/9340 course – Autumn 201637
TEM Viewing Chamber – Phosphorous ScreenFYS 4340/9340 course – Autumn 201638
TEM Image recording CCDs and EELS SpectrometerFYS 4340/9340 course – Autumn 201639
Transmission ElectronMicroscopyIntroduction and BasicsPart-2FYS 4340/9340 course – Autumn 201640
TEM in Materials ScienceThe interesting objects for TEM is not the average structure orhomogenous materials butlocal structure and inhomogeneitiesDefectsInterfacesPrecipitatesAtomic StructureChemical compositionChemical bondingElectronic StructureFYS 4340/9340 course – Autumn 201641
TEM techniquesMain Constrast phenomena in TEMImagingConventional TEMBright/Dark-Field TEMHigh Resolution TEM (HRTEM)Scanning TEM (STEM)Energy Filtered TEM (EFTEM)DiffractionSelected Area Electron DiffractionConvergent Beam Electron DiffractionSpectroscopyElectron Dispersive X-ray Spectroscopy (EDS)Electron Energy Loss Spectroscopy (EELS) Mass thickness Contrast Diffraction contrast Phase Contrast Z-contrastPhase identification, defects, orientationrelationship between different phases, nature ofcrystal structure (amorphous, polycrystalline,single crystal)Chemical composition, electronic states, natureof chemical bonding (EDS and EELS).Spatial and energy resolution down to the atomiclevel and 0.1 eV.FYS 4340/9340 course – Autumn 201642
Objective aperture: Contrast enhancementSiAg and Pbholeglue(light elements)All electrons contributes to the image.Intensity: Thickness and densitydependenceA small aperture allows only electrons in thecentral beam in the back focal plane to contributeto the image.Diffraction contrastMass-thickness contrast(Amplitude contrast)One grain seen along a50 nm low index zone axis.FYS 4340/9340 course – Autumn 201643
TEM techniquesSimplified ray diagram of conventional TEMImagingConventional TEMBright/Dark-Field TEMHigh Resolution TEM (HRTEM)Scanning TEM (STEM)200 nmEnergy Filtered TEM (EFTEM)DiffractionSelected Area Electron DiffractionConvergent Beam Electron DiffractionSpectroscopyElectron Dispersive Spectroscopy (EDS)Electron Energy Loss Spectroscopy (EELS)FYS 4340/9340 course – Autumn 201644
ImagingIncident E-beam(α 22 mrad)specimenscattered E-beamBrightADF FieldADFCourtesy: http://www.ifam.fraunhofer.de; I.MacLauren et al, International Materials Review, 59, 115 (2004)FYS 4340/9340 course – Autumn 201645
ImagingTEMSTEMZGd 64Hf 72Co 27Al 13Gd-Hf-Co-Al quaternary alloysMass thickness and diffraction contrastMass thickness and Z- contrastFYS 4340/9340 course – Autumn 201646
ImagingHRTEMPhase contrastSTEMZ- contrastFYS 4340/9340 course – Autumn 201647
HAADF-STEMABF-STEMHRTEM1.36 ÅRaw HAADF-STEM, ABF-STEM and HRTEM image of Si in the [110] zone axis byFEI Titan 60-300 with spatial resolutions of 0.8 Å for STEM and 2.0 Å for TEM.Courtesy: Wei Zhan, Øystein Prytz, et al. (2015), SMN, UiOFYS 4340/9340 course – Autumn 201648
Electron Diffraction in TEMFYS 4340/9340 course – Autumn 201649
cSimplified ray diagrambaParallel incoming electron beam3,8 ÅSiSample1,1 nmPowderCell 2.0Objective lenseDiffraction plane Objective aperture(back focal plane)Image planeSelected areaapertureFYS 4340/9340 course – Autumn 201650
Electron Diffraction in TEMElastic scattered electronsInelastic scattered electronsOnly the direction of v is changing.(Bragg scattering)Direction and magnitude of v change.Elastic scattering is due to Coulomb interactionbetween the incident electrons and the electriccharge of the electron clouds and the nucleus.(Rutherford scattering).The elastic scattering is due to the averageposition of the atoms in the lattice.Energy is transferred to electrons and atomsin the sample.-It is due to the movements of the atomsaround their average position in the lattice.- It give rise to a diffuse background in thediffraction patterns.Reflections satisfying Braggs law:2dsinθ nλElectrons interacts 100-1000 times stronger with matter than X-rays-more absorption (need thin samples)-can detect weak reflections not observed with XRD techniqueCourtesy: Dr. Jürgen Thomas, IFW-Dresden, GermanyFYS 4340/9340 course – Autumn 201651
Selected area diffraction(SAD) Parallel incoming electron beam and aselection aperture in the image plane. Diffraction from a single crystal in apolycrystalline sample if the SAD aperture issmall enough/crystal large enough. Orientation relationships between grains ordifferent phases can be determined. 2% accuracy of lattice parameters–Convergent electron beam betterImage planeFYS 4340/9340 course – Autumn 201652
Camera constantR L tan2θB 2LsinθB2dsinθB λ R Lλ/dCamera constant:K λLFilm plateFYS 4340/9340 course – Autumn 201653
Indexing diffraction patternsThe g vector to a reflection is normal to thecorresponding (h k l) plane and IgI 1/dnh nk nl(h2k2l2)-Measure Ri and the angles betweenthe reflections-Calculate di , i 1,2,3-Compare with tabulated/theoreticalcalculated d-values of possible phases-Compare Ri/Rj with tabulated values forcubic structure.-g1,hkl g2,hkl g3,hkl (vector sum must be ok)-Perpendicular vectors: gi gj 0-Zone axis: gi x gj [HKL]zOrientations of correspondingplanes in the real space( K/Ri)All indexed g must satisfy: g [HKL]z 0FYS 4340/9340 course – Autumn 201654
Electron Diffraction in TEMAmorphous phasePoly crystalline sampleSingle CrystalsInterface between two different phasesepitaxially grownThe orientation relationship between thephases can be determined with ED.FYS 4340/9340 course – Autumn 201655
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SpectroscopyFYS 4340/9340 course – Autumn 201657
X-ray Energy Dispersive SpectroscopyCu2O (sputtering, 600nm)TiO2 (ALD, 10 nm)AZO (sputtering, 200 nm)Quartz (1mm)We detect the X-rays generated by the sample on a spectrometerEach element has a unique atomic structure and hence a characteristic X-ray energyFYS 4340/9340 course – Autumn 201658
Energy Dispersive X-ray SpectroscopyCu2O (sputtering, 600nm)TiO2 (ALD, 10 nm)AZO (sputtering, 200 nm)Quartz (1mm)FYS 4340/9340 course – Autumn 201659
Electron Energy Loss Spectroscopy (EELS)Inelastically interacted incident electron suffers energy loss after passing through the specimen Phonon ExcitationsInter and Intraband TransitionsPlasmon ExcitationsInner Shell IonizationsCherenkov radiationEach element has characteristic ionization energyowing to its unique atomic structureCourtesy: William & Carter, Transmission Electron Microscopy; EM group, Univ. of Nevada, Reno.FYS 4340/9340 course – Autumn 201660
Electron Energy Loss Spectroscopy (EELS)EELS of the Oxygen K edgeThe reference spectra of Cu2O and CuO arefrom online EELS database1. The referencespectra were shifted in energy to match thefirst O K peak in our experimental, andscaled by the total counts in the energy-loss560-590 eV.Cu2OCuOZnOCourtesy: Cecilie Granerod, SMN, UiO1Ngantcha,Gerland, Kihn & Riviere, Eur. Phys. J. Appl. Phys. 29, (2005) 83.FYS 4340/9340 course – Autumn 201661
Next Lecture TEM Instrumentation – Part 2(Text book Chapters: 5 – 9) TEM Specimen Preparation(Text book Chapters: 10)FYS 4340/9340 course – Autumn 201662
FYS 4340/9340 course – Autumn 2016 1 Diffraction Methods & Electron Microscopy Sandeep Gorantla FYS 4340/FYS 9340 Lecture 2
Introduction of Chemical Reaction Engineering Introduction about Chemical Engineering 0:31:15 0:31:09. Lecture 14 Lecture 15 Lecture 16 Lecture 17 Lecture 18 Lecture 19 Lecture 20 Lecture 21 Lecture 22 Lecture 23 Lecture 24 Lecture 25 Lecture 26 Lecture 27 Lecture 28 Lecture
Nuclear Magnetic Resonance (NMR) 6208 14.487% Electron microscopy 145 0.338% Fiber diffraction (X-ray) 22 0.051% Neutron diffraction 19 0.044% Powder diffraction (X-ray) 17 0.040% Electron diffraction 14 0.033% Electron tomography 4 0.009% Fluorescence transfer 1 0.002% Total 42851 100.000% (at 90% sequence identity April 23, 2007)
Electron Microscopy and X-Ray Crystallography Tianyi Shi 2020-02-13 Contents 1 Introduction 1 2 X-Ray Crystallography 1 3 Cryo-Electron Microscopy 2 4 Comparison of Strengths and Limitations 3 5 Combining X-ray and Cryo-EM studies 3 6 Concluding Remarks 4 References 4 Compare the strengths and limitations of Electron Microscopy and X-ray .
Lecture 9: Introduction to . Diffraction of Light. Lecture aims to explain: 1. Diffraction of waves in everyday life and applications 2. Interference of two one dimensional electromagnetic waves 3. Typical diffraction problems: a slit, a periodic array of slits, circular aperture . 4. Typical approach to solving diffraction problems
Plane transmission diffraction grating Mercury-lamp Spirit level Theory If a parallel beam of monochromatic light is incident normally on the face of a plane transmission diffraction grating, bright diffraction maxima are observed on the other side of the grating. These diffraction maxima satisfy the grating condition : a b sin n n , (1)
Diffraction of Waves by Crystals crystal structure through the diffraction of photons (X-ray), nuetronsandelectrons. 18 Diffraction X-ray Neutron Electron The general princibles will be the same for each type of waves.
Practical fluorescence microscopy 37 4.1 Bright-field versus fluorescence microscopy 37 4.2 Epi-illumination fluorescence microscopy 37 4.3 Basic equipment and supplies for epi-illumination fluorescence . microscopy. This manual provides basic information on fluorescence microscopy
brother’s life ended in death by the hands of his brother. We are going to see what the Holy Spirit revealed that caused the one to murder his flesh and blood. We are also going to see God’s expectation and what he needed to operate in as his brother’s keeper. My desire is for us to all walk away with a greater burden for each other as we see each other as ourselves and uphold each other .
