Introduction to Automatic Crystallographic Orientation Mapping Precession-Assisted in TEM (ASTAR Technique)

Abstract:

In this presentation, Astar tool will be described. By taking control of the electron beam, an area of interest is scanned, and all diffraction patterns are recorded. Precession electron diffraction (PED) [1] is used to increase phase and orientation signature. In a second step, PED patterns are compared to a data base through template matching [2] procedure, results are then presented as phase and orientation maps, using different reliability criteria. The recognition software’s are developed at SIMAP laboratory, whereas the hardware’s are produced by Nanomegas company [3,4]. 

Astar tools is now well established as a powerful characterization tool at the nano and mesoscale to assess phase occurrence or to measure grains at the nanometer scale. Main publications come from metallurgy, semiconductor and minerals communities. In this talk different example of Astar investigation will be presented (figure 1) with a focus on the use of direct detection camera to increase speed of acquisition on sensitive samples [5].

Speaker bio:

Dr. Muriel Veron received her Engineering degree and her PhD in Material Science and Engineering from Grenoble INP, France. After completing her PhD in 1995, she joined the department of Materials Science and Engineering at McMaster University, Canada as a Postdoctoral Research Associate. She became a Professor at Grenoble INP Phelma in 2008. In July 2011, she was awarded APERAM Rene Castro Prize for her contributions in steel phase transformations and alloy design. In the Metal Physics department at SIMaP, her research focuses on the coupling between microstructure and mechanical properties. She works closely with industrial collaborators on fundamental and applied topics. She published more than 120 articles including conference proceedings, animated more that 25 workshop dedicated to cristallography, and supervised 20 PhD students. Muriel Veron has contributed significantly to the development of TEM automated orientation mapping in association with the pioneering work of Dr. Edgar Rauch (CNRS). This tool was coupled with precession electron diffraction, and commercialized under the name of ASTAR (NanoMegas company). It provides the scientific and industrial communities with a new and powerful tool to investigate materials. She is now deputy director of SIMaP laboratory.

References:

1. R. Vincent, P.A. Midgley, Double conical beam-rocking system for measurment of intergrated electron diffraction intensities, Ultramicroscopy 53 (1994) 271.
2. E.F. Rauch, L. Dupuy, Rapid spot diffraction patterns identification through template matching, Arch. Metall. Mater. 50 (2005) 87–99.
3. Orientation and Phase Mapping in TEM Microscopy (EBSD-TEM Like): Applications to Materials Science, Edgar F. Rauch, Muriel Veron, Stavros Nicolopoulos and Daniel Bultreys, Solid State Phenomena vol 186 (2012), pp 13-15
4. Rauch, EF; Veron, M, Automated crystal orientation and phase mapping in TEM, MATERIALS CHARACTERIZATION, v., 98, 2014, IF, 4.342, 10.1016/j.matchar.2014.08.010
5. Jia Hui Lim, Yun Jing, Sung Park, Yoshiharu Nishiyama, Muriel Veron, Edgar Rauch, Yu Ogawa. Structural Anisotropy Governs the Kink Formation in Cellulose Nanocrystals. The Journal of Physical Chemistry Letters 2023, 14 (16) , 3961-39