Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"aberration-corrected"”.
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Electron-beam lithography towards the atomic scale and applications to nano-optics
… We investigated the resolution of EBL using an aberration-corrected scanning transmission electron microscope as the exposure tool at 200 keV. We achieved isolated features with critical dimensions of 2 nm and 5 nm half-pitch in hydrogen silsesquioxane resist. We analyzed the resolution limits …
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Sub-10-nm electron-beam lithography for templated placement of colloidal quantum dots
… and at high electron energy (200 keV) in an aberration-corrected scanning transmission electron microscope. Sub-10-nm structures were fabricated and proximity effects were evaluated in both conditions. As an application of sub-10-nm EBL, this thesis presents a templated-self-assembly …
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Scanning transmission electron microscopy (STEM) and X-ray absorption spectroscopy (XAS) investigations of catalytic systems
… electron microscopy (STEM) or spherical aberration-corrected STEM (Cs-STEM). Although the majority of the work focuses on γ-Al2O3 supported nanoparticles because of their industrial importance for fuel production, several other systems are also addressed. These include understanding the …
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Development of process to transfer large areas of LPCVD graphene from copper foil to a porous support substrate
… electron microscopy, diffraction patterning, and aberration-corrected scanning transmission electron microscopy.
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Stability of nanostructured : amorphous aluminum-manganese alloys
… via three dimensional atom probe tomography and aberration-corrected scanning electron microscopy. The segregation energies were calculated based on the experimental results and compared with the values calculated from a thermodynamic-based segregation model. Upon heating of the nanostructured …
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INVESTIGATION OF ADVANCED IMAGE RECONSTRUCTION ALGORITHMS FOR ELECTRON MICROSCOPY
Aberration-corrected optics have made transmission electron microscopy a widespread and essential tool for 2D/3D material characterization at the atomic scale. With the rapid development of hardware and novel experimental techniques, there is an increasing demand for advanced algorithms to work …
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Structural and chemical characterization of complex nanomaterials at atomic resolution
… and subsequently examined using spherical aberration-corrected STEM (Cs-STEM) and high-energy X-ray diffraction (XRD). Atomically resolved micrographs provide significant insight into the differences in crystallinity and metal-atom bonding between Pt and Pd. The apparent structural …
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Electron microscopy characterisation of size-selected Pd clusters and industrial Pd catalysts
… Specific structural motifs are identified using aberration corrected STEM within the sample range via direct comparison with simulated HAADF-STEM images of structures simulated using global minimum techniques.
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Model systems for the study of active phase evolution in complex bimetallic catalysts (PdZn)
… use of the silica as a TEM support combined with aberration corrected HRSTEM, EDX, XPS and Raman allowed for a very detailed look into PdZn nanoparticle formation from (Pd,Zn)O → α-Pd → β1-PdZn → Pd2Zn and back to α-Pd. This study provided insight into the role of reduction temperature, showing …
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CRYOGENIC MICROSCOPIES OF ENERGY STORAGE MATERIALS: INSIGHTS INTO METAL ANODES, SOLID-ELECTROLYTE INTERFACES, AND MXENES
… transmission electron microscopy (cryo-TEM), aberration-corrected scanning transmission electron microscopy (AC-STEM), and electron energy loss spectroscopy (EELS), we have developed novel analytical approaches that enable unprecedented insights into environmentally and beam-sensitive energy …
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Transmission Electron Microscopy Of Structural Disorder In Two-Dimensional Materials
… the extreme. A second set of projects utilizes aberration-corrected electron microscopy of a newly discovered 2D polymorph of SiO2 to conduct some of the first atomic- resolution studies of glass. Images of the atomic structure of 2D SiO2 strikingly resemble Zachariasen's foundational cartoon …
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X-RAY CHARACTERIZATION OF PLATINUM GROUP METAL CATALYSTS
… information obtained from both XRD and XAS. With aberration-corrected HAADF, particles ranging from sub-nm-size down to clusters of a few atoms and isolated single-atoms can be routinely imaged. A challenge to the interpretation of these images is the characterization of mixed atomic species, in …
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Synthesis, characterization and photovoltaic integration of type II nanorod heterostructures
… structures and develop a technique using an aberration corrected scanning transmission electron microscope to argue a hypothesis as to its cause. In chapter four we develop a synthetic strategy to forming alloyed type II nanorod heterostructures and show that we can tune their heterojunction …
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Transmission Electron Microscopy Study of Domains in Ferroelectrics
… coefficient of resistivity (PTCR) effect. Aberration-corrected STEM and EELS revealed a grain boundary PbTiO<sub>3</sub>-like region (~10-15 nm), which was associated with an increased local polarisation in that region. The chemical and electronic heterogeneity of the ceramic was linked to …
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Structure-property correlations in compositionally complex ferroelectrics
… on using atomic scale characterization with an aberration-corrected scanning transmission electron microscope (STEM) to determine these structure-property correlations in two compositionally complex ferroelectric systems: compositionally heterogeneous relaxors and stoichiometry-controlled …
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Quantitative off-axis Electron Holography and (multi-)ferroic interfaces
… i.e., state-of-the-art instruments facilitate aberration corrected imaging within a large magnification interval covering the length scales of interest, in particular the atomic regime. A general drawback of conventional TEM techniques is the loss of phase information originally contained in …