나노융합기술원(NINT)에서 아래와 같이 TEM-EBSD, Strain Mapping, 3D Diffraction Tomography에 관한 세미나가 있으니 관심있으신 분들의 많은 참석 바랍니다.
- 아 래 -
○ 일시: 10월 31일(목) 14:00-16:00
○ 장소: 나노융합기술원 1층, 컨퍼런스 A홀
○ 제목: Precession Electron Diffraction Applications in TEM:
from crystal structure determination to orientation imaging and
strain mapping at nm scale
○ 연사: V. Stelliou (NanoMEGAS Area Manager)
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KEY WORD: TEM-EBSD(ASTAR), Strain Mapping, 3D Diffraction Tomography
TITLE: Precession Electron Diffraction Applications in TEM: from crystal structure determination to orientation imaging and strain mapping at nm scale
Based on the early work by Vincent and Midgley in Bristol UK (1994) that developed the Precession Electron Diffraction (PED) technique in transmission electron microscope (TEM), PED is an essential tool for several TEM applications for nanomaterials. One of the important applications for electron crystallography , is the recently developed 3D PED diffraction tomography technique allowed from the collection of several PED patterns complete solution of various previously unknown structures from complex zeolites and minerals to metals and alloys.
Another key application including use of PED is the ASTAR technique where is possible to obtain orientation and phase maps at 1-3 nm resolution (in case of FEG-TEM) for a variety of materials (metals, alloys, semiconductors, oxides etc..) . The technique is very similar to EBSD-SEM, but in our case is based on collection of several PED patterns on a crystalline area and template matching with theoretically generated templates. ASTAR orientation imaging can be applied for in-situ TEM strain applications where is important to analyze crystal / grain size textures at different deformation cycles.
Precession diffraction has been recently successfully applied to obtain Strain mapping analysis of several semiconductor materials at 1-4 nm resolution (in case of FEG-TEM, sensitivity 0.02%), based on comparison of NBD patterns from strained /reference un-strained areas. The technique is very easy to use at any TEM and provides very fast and accurate data (same order of magnitude as dark field holography) without any need to index diffraction patterns.
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Speaker: Vrettos Stelliou
Position: Area Manager
Affiliation: NanoMEGAS
Background: I hold a Degree of Physics from University of Athens (Greece) and a Masters of Biomedical Engineering from U.N.S.W Sydney, Australia where I also spent a few years as a research assistant and Ph.D student. I have dual Citizenship (Greek-Australian) and have worked in the Public Sector for both countries. Τhe last 16 years I have been active in the Nanotechnology field collaborating for companies like FEI, Panalytical, Fischione and of course NanoMEGAS
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