Exploring physics of electron microscopy

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We develop the physics of electron-solid interactions underlying electron microscopy (EM). We explore the ultimate limits of practical EM arising from physics and sample radiation damage by the electron beam itself. Applications of the proposed work range from biology to physics, chemistry and materials science. The proposed funding will provide a training opportunity within the EM research program at NRC-NANO, thus leveraging ~20M$ investment at NANO. Graduates capable of developing EM, rather than merely using existing tools, are highly sought after. The funding supports student training in three areas: 1) Quantitative Phase Plate imaging (PPI), refers to the manipulation of the electron wave to increase image contrast and to image radiation-sensitive samples including cells, and virus and protein particles. PPI gained prominence following our invention of the hole-free phase plate. At present, a majority of new cryo transmission electron microscopes are equipped with our phase plate. We have demonstrated quantitative PPI for ultra thin samples and for samples containing only discrete spatial frequencies. We have shown that PPs can simultaneously image sample magnetization and microstructure in focus thus qualitatively improving image interpretation, and perform 3D reconstruction by electron tomography of computer chips and molecular devices. The students will learn quantitative PPI for arbitrary samples, explore new hardware designs for quantitative PPI, and develop new PPI applications. 2) Momentum resolved electron energy loss spectroscopy (qEELS) has been a strength of our laboratory, thanks to our in-house customized transmission electron microscope. We demonstrated that qEELS can be linked to the photonic density of states, and were able to study hyperbolic metamaterials and extreme ultraviolet light sources. We aim to expand research on the optical properties of nanostructured materials thus providing insights needed for the design of future plasmonic devices for telecommunications and information processing. 3) Public-license electron microscopy platform referred to as NanoMi. NanoMi hardware and software will broaden access to EM starting at the college level, thus attracting students of all backgrounds to materials and biological sciences. NanoMi-trained students acquire a deep knowledge of the principles of EM. We are training EM experts who can lead and train EM users. Ultimately, NanoMi will provide a test bench and training platform for future generations of scientists. International interactions with industry and academia contributed to our previous graduate's success. NSERC funding will contribute to the proliferation of a public-license EM that could have enormous impact by enabling EM access, training future experts and stimulating the development of components that can be utilized across numerous fields of science and industry.