Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Physics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 61 - 90 of 1021

Full-Text Articles in Materials Science and Engineering

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs Apr 2025

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs

Senior Honors Papers / Undergraduate Theses

The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …


Exploring Corona Discharge In Electrostatic Printing For Electronics And In Other Application, Zijian Weng Mar 2025

Exploring Corona Discharge In Electrostatic Printing For Electronics And In Other Application, Zijian Weng

USF Tampa Graduate Theses and Dissertations

The field of printed electronics (PEs) is expanding rapidly, driven by increasing market demand. According to reports, the global market for PEs is expected to reach $23 billion by 2026, with a compound annual growth rate of 18.3% from 2023 to 2028. This growth necessitates the development of innovative printing technologies that can meet these demands efficiently, delivering high-quality, high-resolution PEs suitable for applications in health, environmental monitoring, sports, aerospace, and more.

Currently, PEs manufacturing relies on two main groups of printing technologies. Contact printing methods offer high-speed production but struggle with precision, while non-contact methods provide high resolution but …


Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah Mar 2025

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …


Material Classification With Spectropolarimetric Lidar, Alexander J. Watson Mar 2025

Material Classification With Spectropolarimetric Lidar, Alexander J. Watson

Theses and Dissertations

A method for characterizing unknown targets using a hyperspectral polarimetric light detection and ranging (LiDAR) system is presented. Light reflected from manmade objects tends to be more polarized than light reflected from objects in the natural world. As such, polarization measurements can be used in remote sensing applications to differentiate artificial and natural objects. Previous works have attempted to characterize objects through passive polarimetric imagery. Methods developed by Cain and Lemaster and Cunningham facilitate reconstruction of the Stokes Vector from returning light. Martin used multispectral polarimetry to classify targets when the angle of incidence (AOI) is close to 0º. Here, …


Transfer Efficiencies Of Surface-To-Surface Transport Of Micron-Sized Actinide Surrogate Particles, Austin R. Powell Mar 2025

Transfer Efficiencies Of Surface-To-Surface Transport Of Micron-Sized Actinide Surrogate Particles, Austin R. Powell

Theses and Dissertations

Particle effluent of varying sizes is released during routine activities within laboratory environments and these particles can come in contact with a wide range of surfaces. Particles of micron size or smaller can be especially pervasive and can transfer between multiple subsequent surfaces, leading to the progressive contamination of a laboratory. Understanding the transport dynamics of micron sized particles will help inform facility personnel of the possibility of contamination by these potentially hazardous materials of interest. In this research, the transfer efficiency of micron sized surrogate actinide particles (Europium-doped Gadolinium Oxysulfide (EGOS)) is measured for multiple materials, between two particle …


Novel Approach For The Micro Cracks Detection Of Solar Wafers And Cells, Mohd Israil, Arvind Kumar Sharma, Ekta Gupta Jan 2025

Novel Approach For The Micro Cracks Detection Of Solar Wafers And Cells, Mohd Israil, Arvind Kumar Sharma, Ekta Gupta

Al-Bahir

This paper deals with the review of various existing technique for the microcracks detection in silicon solar cell and wafer. In addition to this, we proposed a novel approach for the machine learning technique for the inspection of the cracks those are existed in the solar cell and wafer and not able to detect by the naked eyes. There are many techniques have been developed by the various researchers around the world to inspect solar cells for defect. All the techniques discussed in this article having some features and some weakness too. This paper present here gives the two-fold solution …


Fabrication Of Microscale Oxide Architectures On Silicon Via A Cmos-Compatible, Deposition-Last Process, Jamal A. Brown Jan 2025

Fabrication Of Microscale Oxide Architectures On Silicon Via A Cmos-Compatible, Deposition-Last Process, Jamal A. Brown

Material Science and Engineering Theses - Archive

This work explores the feasibility of integrating complex oxide devices on silicon using a CMOS-compatible, deposition-last approach. While previous demonstrations of this method have succeeded at larger scales, this study focuses on extending the process to microscale features, with lateral dimensions as small as two microns. The fabrication sequence begins with photolithographic patterning and reactive ion etching of the silicon substrate, followed by the deposition of a silicon nitride mask to delineate device regions. We then epitaxially grew SrTiO3 and La-doped SrTiO3 layers on top of the nitride mask via molecular beam epitaxy. Electrical transport measurements of the La:STO layer …


Outgassing Measurements Of Bare And Magnetite-Coated Low-Carbon Steel Vacuum Chambers, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa Jan 2025

Outgassing Measurements Of Bare And Magnetite-Coated Low-Carbon Steel Vacuum Chambers, Aiman H. Al-Allaq, Md Abdullah Mamun, Matt Poelker, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

The outgassing properties of bare and magnetite-coated AISI 1020 low-carbon steel vacuum chambers were evaluated to establish material selection criteria for extreme high vacuum applications, namely, to explore the possibility of using these materials to build next-generation spin-polarized photoelectron guns. Water outgassing measurements using the throughput method revealed that the magnetite-coated chamber exhibited five times lower outgassing at room temperature prior to baking, but this advantage disappears after 80 °C baking. Hydrogen outgassing measurements demonstrated significant differences after intensive heat treatment: the bare low-carbon steel vacuum chamber achieved a specific outgassing rate of 9.6 × 10−16 Torr L s …


Optimizing Superconducting Nb Film Cavities By Mitigating Medium-Field Q-Slope Through Annealing, B. Abdisatarov, G. Eremeev, H. E. Elsayed-Ali, D. Bafia, A. Murthy, Z. Sung, A. Netepenko, A. Romanenko, C. P.A. Carlos, G. J. Rosaz, S. Calatroni, S. Leith, A. Grassellino Jan 2025

Optimizing Superconducting Nb Film Cavities By Mitigating Medium-Field Q-Slope Through Annealing, B. Abdisatarov, G. Eremeev, H. E. Elsayed-Ali, D. Bafia, A. Murthy, Z. Sung, A. Netepenko, A. Romanenko, C. P.A. Carlos, G. J. Rosaz, S. Calatroni, S. Leith, A. Grassellino

Electrical & Computer Engineering Faculty Publications

Niobium films are of interest in applications in various superconducting devices, such as superconducting radiofrequency cavities for particle accelerators and superconducting qubits for quantum computing. In this study, we address the persistent medium-field Q-slope issue in Nb film cavities, which, despite their high-quality factor at low RF fields, exhibit a significant Q-slope at medium RF fields compared to bulk Nb cavities. Traditional heat treatments, effective in reducing surface resistance and mitigating the Q-slope in bulk Nb cavities, are challenging for Nb-coated copper cavities. To overcome this challenge, we employed DC bias high-power impulse magnetron sputtering to deposit …


Beyond The Phonon Gas Model (Pgm): Unraveling The Unique Mechanistic Processes Dictating Thermal Transport In Highly Anharmonic And Disordered Materials, Sandip Thakur Jan 2025

Beyond The Phonon Gas Model (Pgm): Unraveling The Unique Mechanistic Processes Dictating Thermal Transport In Highly Anharmonic And Disordered Materials, Sandip Thakur

Open Access Dissertations

Thermal transport in nonmetallic solids has traditionally been described by the phonon gas model (PGM), in which heat is carried by weakly interacting phonon quasiparticles in an ordered crystalline lattice. However, this model breaks down in materials characterized by strong anharmonicity, dynamic disorder, or structural complexity, features prevalent in many next-generation materials used in energy conversion, optoelectronics, and thermal management. This dissertation investigates thermal transport in such complex materials, including metal halide perovskites (MHPs), covalent organic frameworks (COFs), metal organic frameworks (MOFs), and 2D-3D heterostructures, through large-scale molecular dynamics (MD) simulations and frequency-resolved spectral analyses.

In MHPs, the work reveals …


Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola Jan 2025

Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola

College of Graduate Studies: Theses & Dissertations

Binder-jet 3D printing as a transformative technology in additive manufacturing, offers the ability to fabricate complex structures with diverse materials. This thesis investigates the use of a sustainable tung oil-based resin to create composites, exploring the potential for an eco-friendly alternative to synthetic binders.

The aim of this research is to develop and characterize a bio-based resin formulation, using tung oil as the primary binder, for application in binder-jet 3D printing with sand as the reinforcement. The resin formulation was prepared by combining tung oil, n-butyl methacrylate, divinylbenzene, and di-tert-butyl peroxide in precise proportions, ensuring a balanced mixture that supports …


A Fault-Tolerant Exchange-Coupled Spin-Ensemble Qubit At Elevated-Temperatures, Aniruddha Chakraborty Jan 2025

A Fault-Tolerant Exchange-Coupled Spin-Ensemble Qubit At Elevated-Temperatures, Aniruddha Chakraborty

Theses and Dissertations

This thesis introduces a novel qubit architecture: the ferromagnetic exchange-coupled spin ensemble qubit (E-qubit), designed to address the noise-induced instability. In this work, the time evolution of the ensemble’s density matrix is studied using the Liouville–von Neumann equation. To benchmark against a single-spin qubit, the gate fidelity of an E-qubit is computed in the presence of thermal noise. Coherence time is also analyzed under identical thermal condition and a linear scaling is observed with qubit size . The results show that, at 6 K , the gate fidelity error (0.7 % ) of the seven- spin ensemble is an order …


Preparation Of Mocvd-Grown Photocathodes Containing A Strained Gaas/Gaasp Superlattice, G. Blume, A. Masters, J. Grames, M. Stutzman, M. Grau, S. Marsillac Jan 2025

Preparation Of Mocvd-Grown Photocathodes Containing A Strained Gaas/Gaasp Superlattice, G. Blume, A. Masters, J. Grames, M. Stutzman, M. Grau, S. Marsillac

Physics Faculty Publications

In this work, we investigate heat cleaning options for high-polarization GaAs/GaAsP strained-superlattice (SSL) photocathodes with a distributed Bragg reflector (DBR) that were grown using metalorganic chemical vapor deposition (MOCVD). This was done using a microMott polarimeter at Jefferson Lab to optimize both quantum efficiency and polarization. The fabrication process for MOCVD-grown photocathodes does not allow for the inclusion of an arsenic cap, contrary to what is done when fabricating photocathodes using molecular-beam epitaxy (MBE). Without proper preparation, the performance of MOCVD-grown photocathodes can be limited due to surface contamination. Here, we varied both duration and temperature of the heat cleaning …


Investigation Of New Superconducting Materials For The Next Generation High-Performance Rf Superconducting Cavities For Particle Accelerators, Alex Gurevich, Jean Delayen, Chang-Beom Eom, Gianluigi Ciovati Jan 2025

Investigation Of New Superconducting Materials For The Next Generation High-Performance Rf Superconducting Cavities For Particle Accelerators, Alex Gurevich, Jean Delayen, Chang-Beom Eom, Gianluigi Ciovati

Physics Faculty Publications

In this DOE-funded project DE-SC0010081-020 Old Dominion University (ODU) in collaboration with University of Wisconsin (UW) and Jefferson Laboratory have investigated both experimentally and theoretically electromagnetic response and losses in multilayered superconducting structures made of new SRF materials which can push the field and Q performance limits of accelerating cavities.


Monte Carlo Modeling Of Spin Polarized Photoemission From Gaas At Low Temperatures And Positive Electron Affinity Surfaces, John Rison Callahan Jan 2025

Monte Carlo Modeling Of Spin Polarized Photoemission From Gaas At Low Temperatures And Positive Electron Affinity Surfaces, John Rison Callahan

Graduate Research Theses & Dissertations

Research and development of new photocathode materials are essential to the continuing success and productivity of accelerator technology. High-quality photocathodes characterized by high quantum efficiencies, long lifetimes, low mean transverse energies, and robustness to vacuum environments and operation loads are becoming increasingly essential to the successful operation of the next generation of high brightness accelerator applications. For nuclear and high-energy physics experiments and other applications that rely on spin-polarized electron beams, photocathodes must also demonstrate high electron spin polarizations. The development of state of-the-art spin-polarized photocathodes will require both development of methods to improve the quality of already existing cathode …


Development Of Group Iii-V Quantum Confinement-Enabled Detectors: Bias-Tunable Quantum Well Infrared Photodetector (Qwip) And Quantum Dot Scintillation Detector (Qdsd), Gyana R. Biswal Jan 2025

Development Of Group Iii-V Quantum Confinement-Enabled Detectors: Bias-Tunable Quantum Well Infrared Photodetector (Qwip) And Quantum Dot Scintillation Detector (Qdsd), Gyana R. Biswal

Electronic Theses & Dissertations (2024 - present)

This dissertation discloses the physics, fabrication, characterization, and analysis of two novel types of group III-V semiconductor detectors relying on quantum confinement of carriers, namely voltage-tunable quantum well infrared photodetectors (QWIP) and a high-yield ultrafast quantum dot scintillation detector (QDSD). Both QWIP and QDSD heterostructures presented here were grown on 3” GaAs (001) substrates using molecular beam epitaxy (MBE).

A major part of the dissertation focuses on development of the voltage-tunable QWIPs targeting detection in the mid-wave infrared region (MWIR) (3μm -5μm) and long-wave infrared region (LWIR) (8μm -12μm) with control of sensitivity by the applied bias. The QWIPs utilize …


Investigating The Roles Of Intrinsic Point Defects And Transition Metal Doping In Monolayer And Bulk Tis2, Patrick J. Keeney Jan 2025

Investigating The Roles Of Intrinsic Point Defects And Transition Metal Doping In Monolayer And Bulk Tis2, Patrick J. Keeney

UNF Graduate Theses and Dissertations

Within this thesis, the magnetic and electronic properties of various 1T-TiS2 systems are thoroughly examined using density functional theory (DFT) and scanning tunneling microscopy (STM). Formation energies and electronic implications of intrinsic point defects in bulk TiS2 and monolayer TiS2 are analyzed by approximating a computational monolayer of TiS2 as the surface layer of a bulk sample. This approximation is validated given that intralayer covalent bonding dominates interlayer van der Waals interactions. We conclude that the most energetically favorable intrinsic defects are Ti atoms settling above the outermost S plane and S vacancies. In addition, the …


Frustrated Quantum Magnetism: The Interplay Of Isotropic And Anisotropic Interactions With Application To Α-Rucl3, Evan M. Wilson Jan 2025

Frustrated Quantum Magnetism: The Interplay Of Isotropic And Anisotropic Interactions With Application To Α-Rucl3, Evan M. Wilson

UNF Graduate Theses and Dissertations

We investigate how anisotropic spin interactions, including Dzyaloshinskii–Moriya and Kitaev terms, manifest across quantum spin systems ranging from a single S = 1/2 dimer to molecular spin clusters and layered magnetic materials. Beginning with an exact analysis of the spin dimer, we demonstrate how singlet–triplet mixing induced by Dzyaloshinskii–Moriya interaction directly influences both thermodynamic observables and inelastic neutron scattering spectra. These microscopic fingerprints are then extended to trimer, tetramer, and tetrahedron geometries, where field-induced phase transitions and heat capacity anomalies reveal the interplay between isotropic Heisenberg and anisotropic Kitaev exchanges. In the frustrated zigzag honeycomb lattice, we show that a …


Synthesis And Characterization Of Doped Rare-Earth Zinc Alloys, Partha Das Jan 2025

Synthesis And Characterization Of Doped Rare-Earth Zinc Alloys, Partha Das

Graduate Theses/Dissertations

Rare-Earth-Zinc (RE-Zn) alloys doped with manganese represent a promising class of materials with diverse applications in magnetic, electronic, and thermoelectric devices. These alloys hold significant potential owing to the unique combination of rare-earth elements' properties with the versatility of zinc, augmented by manganese doping. In this study, I present the successful synthesis of ErMn0.2Zn11.8 alloys, achieved through self-flux method. The synthesized crystals were characterized using electron dispersive spectroscopy (EDS) and single crystal X-ray diffraction (XRD). Additionally, magnetic measurements were performed to investigate the magnetic properties. Future plans include DFT calculations and comparison study between Rare-Earth-Zinc alloys with …


First-Principles Study Of Ferroelectric Properties And Co2 Reduction Reaction Capabilities In Two-Dimensional Monolayers And Heterostructures, Mo Li Dec 2024

First-Principles Study Of Ferroelectric Properties And Co2 Reduction Reaction Capabilities In Two-Dimensional Monolayers And Heterostructures, Mo Li

Dissertations

Two-dimensional (2D) materials hold significant potential for CO2 reduction reactions (CO2RR) due to their high surface-to-volume ratio. However, achieving high selectivity for desired products and overcoming limitations posed by scaling relationships remain challenging. Recent studies suggest that ferroelectric (FE) materials with switchable out-of-plane polarization (OOP) can effectively tune the adsorption behavior, thermodynamics, and kinetics of CO2RR, offering promising solutions to these challenges. Using density functional theory (DFT) and the Berry phase approach, this work expands the family of 2D ferroelectrics by theoretically identifying Y2CO2, Y2CS2, and Sc …


A Comparative Study Of Conventional And Statistically Active Corrosion Methods For Corrosion Growth Assessment Of A 24-Inch Gas Pipeline, Rudi Rinaldi, Jaka Fajar Fatriansyah Dec 2024

A Comparative Study Of Conventional And Statistically Active Corrosion Methods For Corrosion Growth Assessment Of A 24-Inch Gas Pipeline, Rudi Rinaldi, Jaka Fajar Fatriansyah

Journal of Materials Exploration and Findings

Component failures in oil and gas pipelines can have fatal consequences, leading to operational downtimes and environmental damage. Knowledge of the corrosion growth rate is fundamental to pipeline integrity management, as it is essential for risk assessment and decisions related to asset management. This article aimed to compare two approaches for the corrosion growth estimation of the 24-inch offshore gas pipeline: the conventional method versus the Statistically Active Corrosion (SAC) method. This article is based on the in-line inspection (ILI) results of two consecutive assessments from 2020 to 2023 of the entire 73 km of the pipeline. The results show …


Ge/Sige Quantum Wells: Material For The Post-Moore Era, Troy Alexander Hutchins-Delgado Dec 2024

Ge/Sige Quantum Wells: Material For The Post-Moore Era, Troy Alexander Hutchins-Delgado

Optical Science and Engineering ETDs

This dissertation demonstrates high-quality germanium quantum wells on a 200 mm silicon wafer platform, enabling novel device possibilities. Partnering with a commercial silicon-germanium epitaxy supplier, we obtained shallow, undoped germanium quantum wells with high-crystalline quality, confirmed through x-ray diffraction, secondary ion mass spectroscopy, high-resolution scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. Hall bar devices fabricated on single quantum wells revealed that surface preparation can tune transport properties while maintaining peak mobilities around 105 cm2V−1s−1. Manganese-germanide spintronic contacts were integrated via solid-state reaction, with contact quality assessed through Schottky diodes, transfer length …


Magnetic Nano And Micro Rods As Tools For Characterizing Materials Mechanical Properties: Fundamentals And Applications, Artis Brasovs Dec 2024

Magnetic Nano And Micro Rods As Tools For Characterizing Materials Mechanical Properties: Fundamentals And Applications, Artis Brasovs

All Dissertations

The focus of this dissertation is insect blood (Hemolymph). Hemolymph is analyzed by taking a materials science approach. Rheological characterization of hemolymph has been performed for the first time. Owing to a minute amount of available material, a new protocol was established where Magnetic Rotational Spectroscopy (MRS) with ferromagnetic nanorods was employed. The challenge was examining the microliter droplets' viscosity in less than a few minutes. This challenge was successfully resolved.

Blood is critical for the insect's survival: after wounding, the insect has to seal the wound quickly, in a few minutes. As the mechanism of fast clotting has never …


Density-Driven Investigations Of Ruthenium Binary Compounds Rux2 (X = O, S, N), Melanie White Dec 2024

Density-Driven Investigations Of Ruthenium Binary Compounds Rux2 (X = O, S, N), Melanie White

UNLV Theses, Dissertations, Professional Papers, and Capstones

Exploration and fine-tuning of the energy landscape of materials can be accessed by means of changes in material density, a key principle of high pressure research. Density-driven changes impact variations in oxidation states and coordination numbers for the element constituents of a compound. Pressure-induced modification of intrinsic density can promote the formation of new materials, variations in physical properties, and transformations in crystallographic symmetry. With this as our foundation, we focus on ruthenium binary compounds - altering the anion species to change electronegativity while probing pressure and temperature effects. This led us to the present study of ruthenium oxide RuO2, …


Advancing Biofabrication Methodologies To Develop Biomimetic Tissue Scaffolds For Musculoskeletal Applications, Nashaita Yezdi Patrawalla Dec 2024

Advancing Biofabrication Methodologies To Develop Biomimetic Tissue Scaffolds For Musculoskeletal Applications, Nashaita Yezdi Patrawalla

Theses and Dissertations

Musculoskeletal injuries impose a significant global burden, affecting millions and generating an economic toll exceeding $14 billion. Tissue engineering has gained traction as a promising strategy offering potential for functional restoration of damaged musculoskeletal tissues. This research aims to advance biofabrication techniques for generation of biomimetic tissue scaffolds, by optimizing scaffold design and modulating fabrication process parameters to generate scaffolds for musculoskeletal regeneration with application-specific tailored properties. In this realm, collagen-based biomaterials have been extensively investigated for tendon and ligamentous applications, and in combination with bioceramics incorporated into the collagen framework to produce composite scaffolds that better recapitulate the native …


Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro Dec 2024

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …


Computational Design Of Complex Concentrated Alloys, Hamid Sharifi Nov 2024

Computational Design Of Complex Concentrated Alloys, Hamid Sharifi

Doctoral Dissertations

A high-throughput parameterization of modified embedded atom model (MEAM) interatomic potentials for combinations of Cu, Ti, Ni, Cr, Co, Al, Fe, and Mn was carried out using a genetic algorithm. Unary systems were parameterized based on DFT calculations and experimental results. MEAM potentials for 28 binary and 56 ternary combinations of the elements were parameterized to DFT results that were carried out with semi-automated frameworks. Specific attention was made to reproduce properties that impact compositional segregation, material strength, and mechanics. Utilizing the MEAM interatomic potentials and a Monte Carlo scheme, phase segregation in the CrNiCo, CuNiCr and CuNiCo fcc alloys …


Quantifying Chemomechanical Weakening In Muscovite Mica With A Simple Micromechanical Model, Jordan J. Sickle, William M. Mook, Frank W. Delrio, Anastasia G. Ilgen, Wendelin Wright, Karin A. Dahmen Nov 2024

Quantifying Chemomechanical Weakening In Muscovite Mica With A Simple Micromechanical Model, Jordan J. Sickle, William M. Mook, Frank W. Delrio, Anastasia G. Ilgen, Wendelin Wright, Karin A. Dahmen

Faculty Journal Articles

In response to gradual nanoindentation, the surface of muscovite mica deforms by sudden stochastic nanometer-scale displacement bursts. Here, the statistics of these displacement events are interpreted using a statistical model previously used to model earthquakes to understand how chemically reactive environments alter the surface properties of this material. We show that the statistics of nanoindentation displacement bursts in muscovite mica are tuned by chemomechanical weakening in a manner similar to how the statistics of model events are tuned by a mechanical weakening parameter that describes how easily system-spanning cracks can be nucleated. Because the predictions of this model are independent …


Insulator-To-Metal Transition And Isotropic Gigantic Magnetoresistance In Layered Magnetic Semiconductors, Gokul Acharya, Bimal Neupane, Chia-Hsiu Hsu, Xian P. Yang, David Graf, Eun Sang Choi, Krishna Pandey, Md Rafique Un Nabi, Santosh Karki Chhetri, Rabindra Basnet, Sumaya Rahman, Jian Wang, Zhengxin Hu, Bo Da, Hugh O.H. Churchill, Guoqing Chang, M. Zahid Hasan, Yuanxi Wang, Jin Hu Nov 2024

Insulator-To-Metal Transition And Isotropic Gigantic Magnetoresistance In Layered Magnetic Semiconductors, Gokul Acharya, Bimal Neupane, Chia-Hsiu Hsu, Xian P. Yang, David Graf, Eun Sang Choi, Krishna Pandey, Md Rafique Un Nabi, Santosh Karki Chhetri, Rabindra Basnet, Sumaya Rahman, Jian Wang, Zhengxin Hu, Bo Da, Hugh O.H. Churchill, Guoqing Chang, M. Zahid Hasan, Yuanxi Wang, Jin Hu

Physics Faculty Publications and Presentations

Magnetotransport, the response of electrical conduction to external magnetic field, acts as an important tool to reveal fundamental concepts behind exotic phenomena and plays a key role in enabling spintronic applications. Magnetotransport is generally sensitive to magnetic field orientations. In contrast, efficient and isotropic modulation of electronic transport, which is useful in technology applications such as omnidirectional sensing, is rarely seen, especially for pristine crystals. Here a strategy is proposed to realize extremely strong modulation of electron conduction by magnetic field which is independent of field direction. GdPS, a layered antiferromagnetic semiconductor with resistivity anisotropies, supports a field-driven insulator-to-metal transition …


Liquid Crystalline Collagen Assemblies As Substrates For Directed Alignment Of Human Schwann Cells, Homa Ghaiedi, Luis Carlos Pinzon-Herrera, Saja Alshafeay, Leonard Harris, Jorge Almodovar, Karthik Nayani Nov 2024

Liquid Crystalline Collagen Assemblies As Substrates For Directed Alignment Of Human Schwann Cells, Homa Ghaiedi, Luis Carlos Pinzon-Herrera, Saja Alshafeay, Leonard Harris, Jorge Almodovar, Karthik Nayani

Chemical Engineering Faculty Publications and Presentations

Collagen is a key component of the extracellular matrix (ECM) and well-oriented domains of collagen are important for mimicking the local cell environment in vitro. While there has been significant attention directed towards the alignment of collagen, formation of large-scale oriented domains remains a key challenge. Type I collagen self-assembles to form liquid crystalline (LC) mesophases in acidic conditions at concentrations above 100 mg mL−1. The LC mesophase provides an efficient platform for large-scale alignment and patterning of collagen coated substrates. However, there still exist challenges related to solubilizing and processing of collagen at such high concentrations in order …