Advanced TEM workshop
Workshop in diffraction
The TEM Gemini Centre at NTNU/SINTEF organized a diffraction workshop in Trondheim 12-14 June this year. Lecturers were Jian Min Zuo, University of Illinois, USA, Christoph Koch, Humboldt University, Germany, Duncan Johnstone, University of Cambridge, UK and Randi Holmestad, NTNU. 27 participants from 16 labs and 11 countries participated, and learned about new developments in electron diffraction. Both theory and practice of electron diffraction were covered, including precession electron diffraction and convergent beam methods. Advanced techniques with rocking and scanning beams were also discussed in the lectures. Three experimental labs were organized where the different diffraction techniques were demonstrated and taught. In the computer labs, a variety publically distributed free programs for simulating and analyzing diffraction patterns were demonstrated and used, including QED, QSTEM and Hyperspy.
Group picture from the workshop. More pictures from the workshop
Lecture notes
Lecture I Randi Introduction, diffraction theory, kinematic and dynamical, overview
Lecture II Jian Min Diffraction techniques, electron probes and detectors, overview
Lecture III Christoph CBED, multi-beam effects, quantitative electron diffraction
Lecture IV Christoph Large angle methods and advanced techniques
Lecture V Jian Min Diffraction indexing, strain mapping, 3D diffraction and tomography
Lecture VI Duncan Precession electron diffraction, scanning precession electron diffraction
Experimental and computer labs
|
Microscope /computer |
Demonstrators |
Sample/ software |
What (keywords) |
|
|
Ragnhild, Ton and Emil |
Si frame with GaAs nanowires |
Demonstrate basics, how to set up correctly specimen and microscope for selected area electron diffraction (SAED) and nanobeam diffraction (NBD) to obtain required information. This includes finding zone axis, making use of different illumination conditions and measuring probe size and convergence angle. |
|
JEOL JEM 2100F Nanomegas ASTAR |
Sigurd and Jonas |
Aluminium alloy |
Demonstrate alignment of precession. Record selected area zone axis diffraction patterns with varying precession angle. Alignment and setup for SPED; probe size, step size etc. Show virtual dark field for phase mapping and diffraction spot indexing. |
|
|
Per Erik and Tina
|
Ga(N)As thin film
|
Brief introduction to ARM and STEM operation. Find an amorphous region, record, examine and discuss Ronchigram. Record [110] zone axis CBED patterns from GaAs from thin and thick regions. Use the t/lamda function to examine sample thickness. Switch to EFTEM mode. Record energy-filtered and non-filtered CBED patterns, record STEM image using the same probe for CBED, diffraction focus. Record energy-filtered PACBED from thin and thick region. Record STEM image using the same probe for PACBED, estimate the probe size. |
|
Computer room
|
Jian-Min |
Crystal structure, supercells etc. Nanocrystals and nanotubes. Crystal diffraction, spot patterns, Kikuchi lines and HOLZ lines, crystal rotation, zone axis and off zone axis, Dynamic diffraction, simulation of CBED patterns, processing, RDF analysis and powder pattern indexing, HOLZ lines, HV determination |
|
|
Computer room |
Christoph |
CBED, thickness and polarity determination, Electron probe formation simulations, Ronchigrams, aberration correction. Dynamic electron diffraction from aperiodic crystals, amorphous structure, nanostructures using multi-slice. |
|
|
Computer room |
Duncan |
Introduction to Python and multi-dimensional data analysis. Virtual Imaging and machine learning. Orientation and strain mapping |
List of participants and organizers
Contact
