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Full-Text Articles in Engineering

Physical Modeling Of Filament Growth And Resistive Switching In Metal Oxide-Based Rram, Kena Zhang Dec 2022

Physical Modeling Of Filament Growth And Resistive Switching In Metal Oxide-Based Rram, Kena Zhang

Material Science and Engineering Dissertations

Metal oxide-based resistive random-access memories (RRAM) exhibit several excellent performances, such as nanosecond switching speed, large write-erase endurance, and long retention time, and can potentially replace the traditional circuit elements for use as the fundamental units in next-generation hardware deep-learning or neuromorphic systems. The functionality of a metal oxide-based RRAM is attributed to an oxygen vacancy (V_O^(..))-rich conductive filament (CF), which initially forms, and later dissolves or regrows inside the oxide layer during the resistive switching process. However, the complicated interplays among the coexisting chemical, electrical, mechanical, and thermal effects during the formation, growth, and rupture of the CFs make …


Phase Field Modeling Of Crack Growth In Shape Memory Ceramics, Ehsan Moshkelgosha May 2021

Phase Field Modeling Of Crack Growth In Shape Memory Ceramics, Ehsan Moshkelgosha

Boise State University Theses and Dissertations

Shape memory ceramics (SMCs) are promising candidates for actuators in extreme environments such as high temperature and corrosive applications. Despite outstanding energy dissipation, compared to metallic shape memory materials, SMCs suffer from a sudden brittle fracture. While the interaction of crack propagation and phase transformation in SMCs has been the subject of several experimental and theoretical studies, mainly at the macroscale, the fundamental understanding of the dynamic interaction of crack propagation and martensitic transformation is poorly understood. This dissertation attempts to provide a mathematical model for crack propagation in transformable zirconia to address the shortage of classical methods. This dissertation …


Multiphysics Phase Field Modeling Of Electromigration, Zachary Morgan Jan 2020

Multiphysics Phase Field Modeling Of Electromigration, Zachary Morgan

Dissertations, Master's Theses and Master's Reports

With the miniaturization of microelectronic devices, the reliability of solder interconnects is a significant concern. As size is reduced, the current density flowing through an interconnect becomes larger and exacerbates electromigration leading to microstructural changes and failure. Since most solder alloys are required to be lead-free over toxicity concerns, there are additional challenges to interconnect performance. Nearly all solder alloys are comprised with its majority component being tin due to its low melting temperature and economical cost. The typical metallic white tin phase has a body-centered tetragonal crystal structure which exhibits strong anisotropy in its physical properties. In particular, the …


Computational Study Of Microstructure-Propertymechanism Relations In Ferroic Composites, Fengde D. Ma Jan 2015

Computational Study Of Microstructure-Propertymechanism Relations In Ferroic Composites, Fengde D. Ma

Dissertations, Master's Theses and Master's Reports - Open

Ferroic materials, as notable members of smart materials, have been widely used in applications that perform sensing, actuation and control. The macroscopic property change of ferroic materials may become remarkably large during ferroic phase transition, leading to the fact that the macroscopic properties can be tuned by carefully applying a suitable external field (electric, magnetic, stress). To obtain an enhancement in physical and/or mechanical properties, different kinds of ferroic composites have been fabricated. The properties of a ferroic composite are determined not only by the properties and relative amounts of the constituent phases, but also by the microstructure of individual …


Diffuse-Interface Field Approach To Modeling Self-Assembly Of Heterogeneous Colloidal Systems And Related Dipole-Dipole Interaction Phenomena, Tianle Cheng Jan 2012

Diffuse-Interface Field Approach To Modeling Self-Assembly Of Heterogeneous Colloidal Systems And Related Dipole-Dipole Interaction Phenomena, Tianle Cheng

Dissertations, Master's Theses and Master's Reports - Open

Colloid self-assembly under external control is a new route to fabrication of advanced materials with novel microstructures and appealing functionalities. The kinetic processes of colloidal self-assembly have attracted great interests also because they are similar to many atomic level kinetic processes of materials. In the past decades, rapid technological progresses have been achieved on producing shape-anisotropic, patchy, core-shell structured particles and particles with electric/magnetic charges/dipoles, which greatly enriched the self-assembled structures. Multi-phase carrier liquids offer new route to controlling colloidal self-assembly. Therefore, heterogeneity is the essential characteristics of colloid system, while so far there still lacks a model that is …