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.
Results
Showing 1 to 20 of 40 for “"in situ TEM"”.
-
In-situ TEM study of carbon nanomaterials and thermoelectric nanomaterials
… widths. They have been extensively studied in recent years due to their high potential for future electronic and spintronic device applications. The edge structures - including the edge roughness and chirality - dramatically affect the transport, electronic, and magnetic properties of GNRs, …
-
In situ TEM investigation of deformation and fracture mechanisms of ceramics and alloys
Limited Restriction Lifted for Item 103359 on 2019-09-30T09:15:20Z.
-
Imaging and Understanding Atomic-Scale Adhesion and Wear: Quantitative investigations Using in situ TEM
The underlying physics governing tribological interactions - adhesion, friction, lubrication, and wear - are poorly understood. Significant progress has been enabled by nanoscale studies using the atomic force microscope (AFM). However, AFM lacks direct access to the contact geometry and structure. …
-
A study of dislocation structures in bulk-strained and in situ TEM strained nickel aluminide alloys
In the research work presented in this thesis, the dislocation structures in bulk strained and in situ TEM strained alloys of hypo-stoichiometric Ni$\sb3$Al with and without boron, and hyper-stoichiometric Ni$\sb3$Al with boron have been studied. Bulk samples were deformed in tension to 3% and 9% …
-
In situ electron microscopy of nanomaterials dynamics in heterogeneous phase environments
Engineered nanomaterials with desired properties and structures are indispensable to catalyze the processes of reliable energy conversion and storage systems for a sustainable future. These functional nanomaterials often experience dynamic physical and chemical changes during the operating cycles. …
-
Novel phase and phase transition behavior of a superionic conductor observed on the nanoscale
This dissertation documents the work performed in the pursuit of a PhD degree in the research group of Prof. Prashant K. Jain at the University of Illinois at Urbana-Champaign. I employed in-situ transmission electron microscopy (TEM) for understanding the ionic structure, vacancy ordering, phase …
-
Domain Switching and Microcracking in Ferroelectric Single Crystals and Polycrystalline Ceramics
In polycrystalline piezoelectric ceramics, electric field-induced cracking occurred by intergranular fracture. The macroscopic path of the crack growth depended strongly upon the applied field and the poling direction. Analysis showed that cracks extended along the place of maximum normal strain. …
-
In-Situ Studies of Copper Nanoparticles Using a Novel Tandem Ultra-High Vacuum Particle Production Chamber Transmission Electron Microscope
… are arguably a new phase of matter whose high grain-boundary-to-volume ratio leads to new and enhanced material properties. Previously, these materials have been difficult to study because of their sensitivity to contaminating atmospheres. We have built a novel apparatus, an ultra-clean …
-
In-Situ Micro Testing Techniques for Electro-Thermo-Mechanical Characterization of Nano/micro-Scale Materials
… deposited at two different conditions and having different grain sizes were compared for their thermal behavior by in-situ TEM annealing. The sample having grain size of 250 nm showed grain growth while that with 55-nm grains displayed no grain growth up to melting. The difference is …
-
Multiscale modeling of two-dimensional materials : structures, properties, and designs
Multiscale modeling undertakes to describe a system with multiple models at different scales. In principle, quantum mechanics provides sufficient information. However, the development of a scaled-up model, e.g., molecular dynamics, from quantum mechanics, should be validated against the …
-
The effects of thermal history and composition on the thermodynamic behaviour of helium in tungsten and tungsten-based alloys
… the demands of the new century. However, containing a plasma with a core temperature ten times hotter than that of the sun is no easy task. The confinement vessel must be constructed from resilient materials that can withstand both the heat and the bombardment of the plasma species. ITER is the …
-
The effects of thermal history and composition on the thermodynamic behaviour of helium in tungsten and tungsten-based alloys
… the demands of the new century. However, containing a plasma with a core temperature ten times hotter than that of the sun is no easy task. The confinement vessel must be constructed from resilient materials that can withstand both the heat and the bombardment of the plasma species. ITER is the …
-
Ceramic interfaces and their radiation response
… are useful due to their various properties, making them the material of choice for many different applications. However, in extreme environments such as one that contains radiation, the physics and the material science of how the ceramic materials change still need to be clarified. In this …
-
Mechanisms Operating During Continuous Dynamic Recrystallization in an Aluminum-4magnesium-0.3scandium Alloy
In-situ TEM experiments were used to directly observe the mechanisms operating during continuous static and continuous dynamic recrystallization. The static process was observed to occur much more rapidly than the dynamic process. The dominant mechanism of continuous static recrystallization …
-
Morphological and Electrical Change of Driven Quantum Dot LEDs
Quantum dot LEDs (QD-LEDs) are an emerging technology that promises brighter, more color pure, higher-color gamut displays. In recent years, indium phosphidenquantum dots have become the one of the most promising device emitters due to their lower toxicity. However, InP QD-LED devices require …
-
A transmission electron microscopy study of inert gases in silicon and iron
This thesis presents a study of inert gas inclusion in iron and silicon, as a result of ionimplantation. The effect of ion implantation conditions on the formation anddevelopment of inert gas bubbles within these solids has been explored, and the mobilityof these nanoscale bubbles during heating …
-
Ion Irradiation Induced Roughening and Smoothing of Metal Films on Dielectric Substrates
This study investigates the morphology evolution of ultrathin Pt films on dielectric substrates produced by heavy ion bombardment. The films roughen and form nanopatterns which coarsen in a certain dose range. The microstructure evolution is characterized using AFM, SEM and RBS. The results are …
-
The effects of irradiation on the creep and hardening behavior of crystalline and amorphous materials
Understanding the mechanical behavior of nanostructured and amorphous materials under harsh environments such as high irradiation dose and temperature is one of the major constraints in the development of novel materials for nuclear applications. This thesis explores the effects of irradiation on …
-
Characterizing Plastic Deformation Mechanisms in Metal Thin Films using In Situ Transmission Electron Microscopy Nanomechanics
… smarter and faster devices has motivated continued research into understanding the mechanical behavior of small-scale materials used to create micron-sized features for devices such as flexible or stretchable electronics or micro electromechanical systems (MEMS). Nanocrystalline (NC) and …
Page 1 of 2