Local probing of structure and property in dimensionally confined amorphous and crystalline structures by S/TEM

The characterization of materials' microstructure has been brought up to a new level since the invention and broad application of transmission electron microscope (TEM) thanks to the high-energy electron beam source which guarantees an unsurpassable spatial resolution and theoretical study of interaction between electron and matter. The advent of nano-world has imposed an urgent request to characterize nano-assemblies in nano- or even sub-nano-scale and scanning transmission electron microscopy (STEM) which typically utilizes an electron probe with a size of 1nm or even smaller has found its unique advantage to unravel the local structure, chemical and physical properties of these emerging nanostructures. Dimensionally constrained nanostructures such as thin films and nanopatterned systems have attracted people's attention for decades due to their novel chemical and physical properties and popularity in energy storage, biological integration and etc. This dissertation focuses on the unique characterization capability of S/TEM to study the local order in amorphous transparent conducting oxide thin films, disordering in 2-D layered materials, localized surface plasmons in nanoporous gold patterns on 2-D layered structures and crystallization process in dimensionally and spatially constrained oxide nanopatterns observed by in-situ TEM.;Electron diffraction and x-ray diffraction are commonly used techniques to study the crystallinity in a certain material - crystalline or amorphous. In amorphous materials which lack long-range order, normal electron diffraction and x-ray diffraction techniques won't be able to extract any useful information regarding the ordering or disordering in the materials. We have developed a unique set of electron diffraction methods in both TEM and STEM, combined with density functional theory molecular dynamics of liquid quench to study the short-range (< 1 nm) and medium-range order (between 1 nm and 3 nm) in amorphous transparent oxide films grown by pulsed laser deposition method.;Graphene and graphene-like 2-D materials have raised people's passion to fabricate atomically thin electronic devices. Among various nanopatterning techniques, electron beam lithography has long been a standard way to fabricate nanostructured devices on designed substrates. The second part of the thesis will report a novel way to pattern gold nanostructures on single-layer graphene and MoS2 and then transfer the composites onto quantifoil TEM grids to enable the probing of localized surface plasmons in gold nanopatterns by low-loss electron energy loss spectroscopy in STEM.;With the advantages of structure characterization by S/TEM, in-situ heating amorphous oxide nanopatterns derived from sol-gel will enable the observation of nucleation and growth in real time and study the effect of dimensional and spatial constraints to the crystallization process. At the end of the dissertation, a nanopatterned system will be investigated in-situ by TEM for the understanding of crystallization process under the constraints from dimension.