Acquisition of an Imaging Filter for an Analytical Electron Microscope

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9802839SarikayaThis award provides partial support to acquire a post-column imaging filter, to be interfaced to an ultra-high-resolution 200 keV analytical transmission electron microscope. The resultant high-resolution, energy-filtering transmission electron microscope (EFTEM) will be employed in a wide range of multidisciplinary research and materials science projects at the University of Washington.The instrument will be used to: (i) map the distribution of most elements in thin samples and probe the sample's chemistry with a spatial resolution of 0.5-2 nm in about one minute for a 512 x 512 pixel map; (ii) digitally record energy-filtered high resolution EM images and diffraction patterns with precision that will revolutionize our ability to analyze materials quantitatively; and (iii) acquire data by electron energy loss spectroscopy and associated techniques, such as energy loss near-edge and extended edge fine structure analyses (ELNES and EXELFS), with unprecedented sensitivity and signal-to-noise ratio. Owing to the high-quality objective lens of the microscope, the obtainable spatial resolution in elemental maps will be about 0.5 nm, i.e. significantly better than the resolution that can be achieved in most energy-filtering systems. The wide range of capabilities made possible by the instrument will revolutionize the way structures can be analyzed in many areas of materials science, condensed matter physics, chemistry and biology at the University of Washington and in the whole Pacific Nrorthwestern geographical region. The instrument will be employed extensively in courses on materials science characterization at UW, and it will also serve to deepen the extensive collaborations we have with local and national companies and various government and university laboratories.Among the materials to be investigated are: (i) Biomimetic and biological materials: interfaces and problems related to templating for inorganic growth; (ii) Microelectronic devices: interfaces, diffusion, oxide compositions, dielectric properties, and dopant distrubutions; (iii) Ferroelectrics and dielectrics: local structures/properties, and compositional variations; (iv) Ceramic composites and glasses: structure and composition profiles, spinodal decomposition in glass matrices.The nano-scale composition and chemistry in materials research are the keys to understanding and controlling the macroscopic properties of materials. All the materials to be studied with the instrument are of very high scientific and industrial importance. The instrument will allow the materials to be imaged at atomic resolution, their composition to be studied at nm-level resolution, and their bonding and electronic properties to be investigated. Our research will also focus on advancing the capabilities of electron energy loss spectroscopy (EELS) towards reliable single atom detection. In particular, detection limits will be studied aiming to extend the attainable minimum detectable mass fraction into the parts per million range. The improved technique will be applied in areas such as dopant detection in semiconductors and ionic concentrations in biological materials. Our previously developed techniques in the ELNES and EXELFS areas will be made much more powerful by the excellent probe-forming capabilities of the 002B, and we will apply them to a braod range of advanced materials. We also plan to develop spectrum imaging with the new instrument and optimize it so that it can produce reliable elemental maps of elements present in concentrations of less than 1 part per thousand.%%%***