Ceramic Materials Commons^™

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

Empirical Modeling Of Structural Distortions In Perovskite Ceramics, Evan Connor Smith

Boise State University Theses and Dissertations

Predictive models for composition-structure-property relationships are essential to realizing the full potential of electroceramic materials; however, the electroceramics industry has largely failed to invest in predictive models in favor of simple rules of thumb or expensive, time-consuming trial-and-error methods. Empirically derived predictive models have the potential to significantly improve and guide future research in a more cost-effective and timely manner. It may even be possible to predict some intrinsic properties (e.g., polarization) on the order of a unit cell using only the charge and size of each chemical component. Scientists and researchers may ultimately be able to use …

Empirical Models For Structural Effects Of A-Site Point Defects And Ordering In Perovskites, Kevin Ross Tolman

Boise State University Theses and Dissertations

Composition-structure-property relationships are essential keys to unlocking the strength of predictive crystal chemistry. Awkwardly, the electroceramics industry largely relies on various time-consuming and expensive trial-and-error experiments to address new questions which often could otherwise be interpolated from published data. Indeed, predictive models, which can be derived from empirical evidence, can greatly aid the direction and support of future development in a meaningful, apt, and cost-effective way. Theory suggests that intrinsic properties on the scale of a unit cell may be estimated from the sizes and charges of the chemical constituents alone. Ultimately, researchers could be provided a compositional recipe for …

Thermoelectric Half-Heuslers: Synthesis, Processing, And Performance, Joseph Robert Croteau

Boise State University Theses and Dissertations

Thermoelectric half-Heusler compounds have potential to convert the heat wasted from industrial and transportation processes to useful electricity. Among the highest performing half-Heusler compounds are nano-structured bulk materials which have been arc-melted, pulverized into a nano-powder, and sintered by DC-hot press. High performing n- and p-type half-Heusler compounds with nominal composition of Hf_0.25Zr_0.75NiSn_0.99Sb_0.01 and Nb_0.75Ti_0.25FeSb, respectively, have been provided to us in both dense and powder form by our collaborators at the University of Houston. We consolidate these powders by SPS, refine these powders to improve both particle size …

Cermet Development For High Temperature And High Pressure Applications, Beatriz Justus Ferez, Samantha Guthrie, Brian J. Jaques (Mentor), Darryl P. Butt (Mentor)

Idaho Conference on Undergraduate Research

Many traditionally used low cost alloys are easily corroded in steam or supercritical CO₂. An effective solution is to utilize ceramic heat exchangers that are often integrated with metallic components which result in a significant thermal expansion mismatch. The goal of this project is to develop a sealing method to create a hermetic joint between the ceramic and metal alloy. Proposed is a seal ring containing a cermet powder with a coefficient of thermal expansion (CTE) higher than the ceramic and metal to produce a high temperature compressive seal. Cermets of Ag and MgO have been selected to …

Computational Studies Of Grain Boundary Behavior In Uranium Dioxide Nuclear Fuels, Eric Nelson, Lan Li (Mentor), Simon C. Middleburgh (Mentor)

Idaho Conference on Undergraduate Research

Nuclear power is responsible for the production of 380,000 Megawatts of energy worldwide, which results in over 11% of the world’s energy production [world-nuclear.org]. Pellet-cladding interactions (PCI) are a key nuclear fuel failure mechanism which presents formidable challenges to researchers due to extreme nuclear fission conditions. Although PCI interactions have been reduced due to fuel additives, understandings of PCI interactions remain elusive. We propose new approaches to increase understanding of nuclear fuel interactions; specifically, uranium dioxide and the effects of dopants. This study focuses on amorphous uranium dioxide and fission products, while benchmarking new methods with previous computational studies. Results …

Verifying The Implementation Of An Anisotropic Grain Boundary Energy Model In Idaho National Lab’S Marmot, John-Michael H. Bradley, Evan D. Hansen, Jarin C. French, Yongfeng Zhang (Mentor)

Idaho Conference on Undergraduate Research

This work aims to verify the correct implementation of an anisotropic grain boundary (GB) energy model for face-centered cubic (FCC) and fluorite materials in Idaho National Laboratory’s phase field fuel performance code MARMOT. The model was recently implemented in MARMOT with the purpose of enabling higher fidelity simulations of UO₂ nuclear fuels. As part of verification, tests were performed to measure the energy dependence on misorientation of high symmetry GBs in an FCC metal (Cu). The energies of the [100], [110], and [111] twist boundaries result as predicted, as do the energies of the [111] symmetric tilt boundaries. However, …

Reaction Kinetics Of Rare Earth And Actinide Materials, Brian Jon Jaques

Boise State University Theses and Dissertations

This dissertation presents the effects of atmosphere, time, and energy input (thermal and mechanical) on the kinetics of gas-solid and solid-solid reactions in systems of dysprosium, uranium, oxygen, and nitrogen. Accordingly, Chapter Two presents a novel synthesis technique used to form DyN via a gas-solid reaction between dysprosium and nitrogen. DyN was rapidly formed through a mechanochemical process in a high energy ball mill at ambient temperatures. The progress of the reaction was quantified using in situ temperature and pressure measurements coupled with microscopy and x-ray diffraction. It was found that the rate of the nitridation reaction is controlled by …

The Electronic And Thermodynamic Properties Of Ca Doped Lafeo3: A First Principles Study Using Density Functional Theory, Davis George Daniel

Boise State University Theses and Dissertations

Density functional theory (DFT) was used to evaluate the electronic and thermodynamic properties of Ca-doped LaFeO₃ (La_1-xCa_xFeO_3-y). La_1-xCa_xFeO_3-y exhibits ionic (O^2- anions) and electronic conductivity at high temperatures and has potential applications in gas separation, syngas production and solid oxide fuel cell cathodes. DFT is a computational technique based on the First Principles of physics, derived from the theory of quantum mechanics. DFT approximates the ground state energy of a system and can subsequently determine many bulk properties such as lattice constants, magnetic states, band gap, density …

Thermodynamics And Reaction Kinetics During Mechanochemical Synthesis And Environmental Testing Of Lanthanide And Actinide Refractory Materials, Gordon Andrew Alanko

Boise State University Theses and Dissertations

High energy ball milling is a broad family of well-known techniques for materials processing that includes mechanochemical synthesis, in which the milled materials react during milling. The latter may involve components reacting in the solid, liquid, or gas phases, and the operative kinetics have hardly been studied. Several manufacturers of high energy ball mills have recently made available instrumented milling vessel lids. These lids are able to monitor the temperature of the lid and the gas pressure within the vessel in situ during milling experiments. This ability is a significant improvement over the ad hoc instrumentation setups sometimes discussed in …

Phase Transformations In Calcium Substituted Lanthanum Ferrite, Patrick M. Price

Boise State University Theses and Dissertations

Increasing world energy demands are still heavily dependent on fossil fuels. To meet these demands, crude oil is increasingly being extracted from remote locations where natural gas pipelines do not exist. It is not profitable for oil and gas companies to transport natural gas by ship or truck from these remote locations so it is combusted on site in the form of gas flares. Critics oppose this practice due to the environmental impact from pollution and carbon emissions created during the flaring process. Oil and gas companies are eager to find profitable ways to eliminate natural gas lines in order …

Impact Of Alkaline Doping And Reducing Conditions On Lafeo3, Geoffrey L. Beausoleil

Boise State University Theses and Dissertations

Efficient and reliable materials for gas separation, syngas production, and hybrid nuclear power plants must be capable of reliably operating at a high-temperature range of 700-1000°C and under exposure to highly oxidizing and reducing conditions. Candidate materials for these applications include alkaline metal doped lanthanum ferrite.

In the first study, the impact of A site substitution by different alkaline metals on lanthanum ferrite (LMF, M=Ca, Sr, and Ba) was investigated. The study focused on thermal expansion near the Néel transition temperature and a magneto-elastic contribution to thermal expansion was identified for each sample. Iron oxidation, Fe³⁺ to Fe^{4+ …}

Recrystallization Kinetics Of 3c Silicon Carbide Implanted With 400 Kev Cesium Ions, Daniel Denell Osterberg

Boise State University Theses and Dissertations

Polycrystalline 3C silicon carbide was implanted at room temperature with 400 keV cesium ions to a dose of 10¹⁶ ions·cm^-2. The samples were then annealed at 600 – 1000°C for 0-48 hours in ultra-high purity argon. The implanted zone of each sample was characterized by transmission electron microscopy and secondary ion mass spectroscopy. It is shown that the implantation resulted in a 217 ± 2 nm amorphous region with microstructural damage extending to approximately 250 nm below the surface. Recrystallization of the amorphous region was observed at 725°C, although minimal densification was observed until ≥ 800°C. Densification …

Repairing Mixed-Conducting, Ceramic Electrolyte Films, Kevin Tolman, Izaak Williamson, Kokfoong Chan

College of Engineering Poster Presentations

Ceramatec, Inc. develops ceramic-electrolyte thin films for gas separation/purification technologies. Specific ions (e.g., oxygen) can be selectively diffused through these films in order to obtain a desired product, such as syngas or pure O2. During production, residual stresses develop within the films which induce defects, such as pinholes, micro-cracks, and other sources of leaks, that allow gas contamination. To improve large-scale film production yield, four application techniques were analyzed for their feasibility of restoring the integrity of the films. Controlled, uniform defects were introduced to the films using a microindenter to enable an effective comparison of application techniques …