New Analytical Techniques using Electron Microscopy for Nano-Materials Characterization in the 0.5 - 30 keV Range

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This CRD aims to further develop characterization techniques with the new SU-9000 CFE-SEM acquired by the applicant in 2017 via a CFI as well as on the SU-8230 CFE-SEM. The SU9000 microscope provides advanced STEM capabilities, especially in the form of specific new transmission mode detectors such as bright-field (BF) and dark-field (DF) detectors, an on-axis diffraction camera for convergent beam electron diffraction (CBED) and a unique low voltage electron energy-loss spectrometer (EELS). (1) The EELS technique at low voltages such as 20 and 30 kV will be studied to understand the impact of low beam energy on its operation and its limitations in order to improve its applicability to a wide range of materials. The possibility of reducing further the beam energy below 20 kV will be investigated. (2) Quantitative low voltage CBED applied to several crystalline systems will be studied to propose a convenient procedure to use this new SEM technology as well as apply post-processing techniques to produce useful results with the technique, which are lacking for now. Its limitations will be assessed as well. (3) The new e-Flash high-resolution electron backscatter diffraction (EBSD) camera from Bruker Inc., installed on the SU8230, will also be tested to define its ability in providing CBED in STEM mode in a state-of-the-art SEM. (4) Finally, since the SU9000 is fitted with the new windowless Extreme x-ray detector from Oxford Instruments, very low voltage x-ray microanalysis will be developed in the range of soft x-rays (0 - 1 kV) since this energy range benefits the most of the absence of a protective window on this type of detectors.