Electron Microscopy for Catalyst Characterization Dr. King Lun Yeung Department of Chemical Engineering Hong Kong University of Science and Technology.

Slides:



Advertisements
Similar presentations
Ge 116 Module 1: Scanning Electron Microscopy
Advertisements

Basic Electron Microscopy
Introduction to Electron Microscopy
Focused ion beam (FIB) 1.Overview. 2.Ion source and optics. 3.Ion-solid interaction, damage. 4.Scanning ion beam imaging. ECE 730: Fabrication in the nanoscale:
SEM & TEM in Polymer Characterization
Catalysis and Catalysts - TEM and SEM Principles of Electron Microscopy (EM)  Resolution strongly dependent of wavelength: –electron microscope: about.
BY Assistant Professor Dr. Akram R. Jabur Department of Materials Eng. University Of Technology.
Saeedeh Ghaffari Nanofabrication Fall 2011 April 15 1.
Electron-Specimen Interactions
Synchrotrons A synchrotron is a ring which uses magnets and electrodes to accelerate x-rays or light to nearly the speed of light These extremely bright.
What are Electron Microscopes? Electron Microscopes are scientific instruments that use a beam of highly energetic electrons to examine objects on a very.
Scanning Electron Microscope (SEM)
Fire Protection Laboratory Methods Day
Groups: WA 2,4,5,7. History  The electron microscope was first invented by a team of German engineers headed by Max Knoll and physicist Ernst Ruska in.
Electron-Specimen Interactions
Lecture 5.1 Scanning Electron Microscopy (SEM)
Lab meetings Week of 6 October
Scanning Electron Microscope Jamie Goings. Theory Conventional microscopes use light and glass lenses SEM uses electrons and magnetic lenses to create.
Activities during UK-Japan Young Scientist Workshop Dr Riz Khan Room 31DJ02, x6062, Advanced Technology Institute University.
Drs. Wei Tian & Yanhui Chen Sep-Dec Microscopic technique Scanning Electron Microscope (SEM) Transmission Electron Microscope (TEM) Atomic Force.
FYSZ460 Electron Beam Lithography Electron Beam Lithography FYSZ460 Advanced Laboratory Exercise Mikko Palosaari
Introduction to scanning electron microscopy
BY SANTANU PRAMANIK(09369) HITESH KUMAR GUPTA(09320) CHANDAN SINGH(09260) SCANNING ELECTRON MICROSCOPE MATERIAL SCIENCE ASSIGNMENT.
Do it with electrons !. Microscopy Structure determines properties We have discussed crystal structure (x-ray diffraction) But consider now different.
LECTURE 5 Principles of Electron Microscopy (SEM and TEM)
Transmission Electron Microscopy
Scanning Electron Microscopy
Auger electron spectroscopy is a surface sensitive analytical technique used mainly to determine elemental compositions of material and, in certain cases.
BMFB3263 Materials Characterization
SEM (SCANNING ELECTRON MICROSCOPE) Özgen Buğdaycı Elif Topçuoğlu Yavuz Duran Hacettepe University
Nano-Materials Characterization Yoram Shapira, EE Nano-bio-electronics Growth and Processing Characterization and Analysis Design and Modeling.
Electron Microscopy 1 Electron Microscopy (EM) Applying Atomic Structure Knowledge to Chemical Analysis.
Electron Microscopes Used to count individual atoms What can electron microscopes tell us? Morphology – Size and shape Topography – Surface features (roughness,
Scanning Electron Microscope (SEM)
Other modes associated with SEM: EBIC
NANO 225 Micro/NanoFabrication Electron Microscopes 1.
Reminders for this week Homework #4 Due Wednesday (5/20) Lithography Lab Due Thursday (5/21) Quiz #3 on Thursday (5/21) – In Classroom –Covers Lithography,
Proximity Effect in Electron Beam Lithography
NANO 230 Micro/Nano Characterization
Scanning capacitance microscopy
SEM- Schematic Overview. Electron Detection Tungsten Filament Electron Source.
Characterization of Nanomaterials…
08/03/09 SEM signal generation
SEM Scanning Electron Microscope
Center for Materials for Information Technology an NSF Materials Science and Engineering Center Substrate Preparation Techniques Lecture 7 G.J. Mankey.
CAREER: Synthesis and Electronic/Electrical Properties of Carbon Nanotube Junctions Wenzhi LiFlorida International UniversityDMR One of the objectives.
SARDAR PATEL INSTITUTE OF TECHNOLOGY E.NO : Guide By:- V.N.Thakkar.
Comparison b/w light and electron microscopes LIGHT MICROSCOPE ELECTRON MICROSCOPE Magnification can be done upto 2000 times Resolving power is less.
Scanning Transmission Electron Microscope
Do it with electrons !. Microscopy Structure determines properties We have discussed crystal structure (x-ray diffraction) But consider now different.
Microscopy.
Scanning Electron Microscope Eee-Jay Rodriguez. The Structure of the Microscope Inside Outside.
BY GAJENDRA KUMAR ID- 2011uit1721. WHAT IS SEM  It is a microscope that uses a focused electron probe to extract structural and chemical information.
Mohammed Zeeshan BT/PE/1601/ Microtexture: Electron Diffraction in the SEM Texture And Microstructure & Anisotropy.
Introduction to scanning electron microscopy
Presentation on SEM (Scanning of Electron Microscope) Represented by:-Ravi Kumar Roll:- (BT/ME/1601/006)
Introduction to scanning electron microscopy
Laboratory equipment Lecture (3).
Introduction to Scanning Electron Microscope by Sameer S
NANO 230 Micro/NanoFabrication
TEM and SEM.
TEM (Transition Electron Microscope)
Cell Biology Practical TEM&SEM
Do it with electrons !.
Nanocharacterization (III)
Electronics and Instrumentation Vidnyan Mahavidyalaya, Sangola.
Nanocharacterization (II)
Types of Microscopy Type Probe Technique Best Resolution Penetration
MICROSCOPES.
Energy dispersion x-ray ( EDX) resulting as incident electron strike unexcited atoms, electrons from inner shell will be ejected and leave a hole. Electrons.
Presentation transcript:

Electron Microscopy for Catalyst Characterization Dr. King Lun Yeung Department of Chemical Engineering Hong Kong University of Science and Technology CENG 511 Lecture 3

Electron-Specimen Interaction e-e- e-e- e-e- backscattered e - elemental contrast secondary e - surface topography Primary or unscattered e - projected sample image transmission electron microscopy

Specimen Interaction Volume (V i ) Auger secondary e- backscattered e- K X-ray L X-ray increasing depth surface information bulk information V i  when accelerating  V i  when incident angle  V i  when atomic number 

Electron-Specimen Interaction Backscattered electrons Topography (A-B) Composition (A+B)

Electron-Specimen Interaction Secondary electrons

Electron-Specimen Interaction Ugly BUGS

Electron-Specimen Interaction Surface Topography of Catalyst-related Materials

Electron-Specimen Interaction Primary or unscattered electrons diamond gold TEM

Electron-Specimen Interaction e-e- e-e- e-e- X-rays bulk elemental composition Auger electrons surface elemental composition Cathodaluminescence band-gap energy, electronic property

Electron-Specimen Interaction Cathodaluminescence

Electron-Specimen Interaction Cathodaluminescence Ion implanted silicon patterns

Electron-Specimen Interaction X-rays Sampling volume for X-ray X-rays Si(Li) detector

Electron-Specimen Interaction Si(Li) Detector   E   Ne -  PULSE 1 PULSE 2

Electron-Specimen Interaction Si(Li) Detector Window

Electron-Specimen Interaction Energy Dispersive X-ray Spectroscopy Si (bright)Al (bright)

Electron-Specimen Interaction Auger Electron WKWK WLWL WMWM WNWN WGWG KK KK LL Auger e - or Auger e -   Z 

Scanning Electron Microscopy specimen Electron gun

SEM - Electron Gun

SEM - Electromagnetic Condenser Lenses

Figure C-8. The light optics (4) and scanning coils (1) are located inside the minicoil probe- forming lens (2) at the base of the electron column. The pole piece (7) is one solid piece of metal and protects the sample from stray magnetic fields. The x-ray beams (3) are collimated by small apertures (6), and pass through an electron trap (5) that prevents backscattered electrons from entering the x-ray pectrometers. SEM - Objective Len

SEM - Electron Probe

SEM - Image Formation-1

SEM - Image Formation-2

Scanning Electron Microscopy high voltage low voltage Effect of accelerating voltage

Scanning Electron Microscopy Effect of accelerating voltage

Scanning Electron Microscopy Effect of beam current and spot size

Scanning Electron Microscopy Effect of accelerating voltage

Scanning Electron Microscopy Effect of accelerating voltage

Scanning Electron Microscopy Incorrect alignment of objective aperture

Scanning Electron Microscopy Effect of specimen tilt Stereo microscopy

Scanning Electron Microscopy Effect of accelerating voltage (1) (2) (3)

Scanning Electron Microscopy Contrast and brightness

Scanning Electron Microscopy Astigmatism

Scanning Electron Microscopy Sample charging

Scanning Electron Microscopy Preventing charging by thin film coating

Scanning Electron Microscopy Electron beam damages and contamination Carbon contaminant deposited by electron beam Electron beam damage on a fly’s compound eye

Scanning Electron Microscopy Sources of image distortions

Scanning Electron Microscopy Influence of external disturbances

Scanning Electron Microscopy Importance of sample preparation

Electron-Specimen Interaction e-e- e-e- e-e- backscattered e - elemental contrast secondary e - surface topography Primary or unscattered e - projected sample image transmission electron microscopy

Electron-Specimen Interaction Principle of E. M. lithography Polymer resist Substrate

Electron Beam Lithography Micropatterning and Microfabrication PMMA resist E-beam develop resist selectively etch substrate

Microfabricated Catalysts deposit alternate layers of catalyst and inert micropattern and etch undercut and remove 50 nm nickel, 50 nm SiO 2

Supported Catalysts Metal supported on metal oxide Coarsening

Microfabricated Catalysts Zeolite micropatterned catalysts Zeolite Grids (200)/(020)(101) Zeolite Grids

Electron-Specimen Interaction Electron beam Thin sample Unscattered electrons

Different Types of Electron Microscopy SEM TEM Ultra-TEM HREM

Transmission Electron Microscopy Au/SiO 2

Electron-Specimen Interaction

Transmission Electron Microscopy Au

Transmission Electron Microscopy Primary or unscattered electrons diamond gold TEM

Transmission Electron Microscopy Catalyst particle size distribution

Transmission Electron Microscopy Catalyst particle shape and morphology

Particle Morphology Selected zone dark field imaging (SZDF) ? ?

Particle Morphology Selected zone dark field imaging (SZDF)  (100) (110)

Particle Morphology Weak beam dark field (WBDF) 

Particle Morphology SZDF and WBDF techniques

Electron-Specimen Interaction

Transmission Electron Microscopy Distribution of crystallographic planes

Electron-Specimen Interaction

High Resolution Electron Microscopy Bismuth molybdates (Bi 2 Mo 3 O 12 -  )

High Resolution Electron Microscopy Bismuth molybdates (Bi 2 MoO 6 -  )

High Resolution Electron Microscopy Platinum on Alumina hydrogen Hydrogen sulfide

High Resolution Electron Microscopy 2 x 1 reconstruction of (110) surface of Au particle

High Resolution Electron Microscopy Rh/SiO 2 Reduced Oxidized

High Resolution Electron Microscopy Rh particles

High Resolution Electron Microscopy Electron-beam induced reduction of RuCl 3 on MgO

High Resolution Electron Microscopy Hydrogen reduced Rhodium-TiO 2

Electron-Specimen Interaction