Condensed Matter Physics Commons^™

Optical, Mechanical, And Transport Characterization Of Two-Dimensional Magnetic Materials., Hiruni Weerahennedige

Electronic Theses and Dissertations

This work investigates the structural, magnetic, thermoelectric, and optoelectronic behavior of layered two-dimensional (2D) materials, with emphasis on Fe₃GeTe₂, Ni-substituted Fe₃GeTe₂ alloys, and GeSe. The study aims to clarify how dimensionality, alloying, and external perturbations influence charge transport, magnetic ordering, and light-matter interactions in van der Waals crystals. Single crystals of Fe₃GeTe₂ and (Ni_xFe_1-x)₃GeTe₂ (x = 0-1) were synthesized by chemical vapor transport and characterized using X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. Angle-resolved polarized Raman spectroscopy resolved symmetry-dependent phonon modes and …

Plasma-Enhanced Carbon Nanomaterial Synthesis: A Pathway To Reducing Greenhouse Gasses And Carbon-Based Waste., Zane Ronau

Electronic Theses and Dissertations

This research leveraged incorporation of capacitively coupled radio frequency plasma into chemical vapor deposition (CVD) for a reduction in the temperature requirements [a reduction of energy barrier] needed for the conversion of methane (CH₄), carbon dioxide (CO₂), and various carbon-based-waste to produce value-added carbon nanomaterials. An array of catalysts and catalyst supports were employed to optimize the synthesis of graphitic carbon under various gas environments, temperatures and pressures. The nanomaterials synthesized after fine tuning the growth parameters included graphene, carbon nanotubes (CNT), carbon microtubes and carbon nanocages with a variety of properties. Raman Spectroscopy was used …

First Principles Calculation Of Electron-Phonon Coupling In Nonequilibrium Quantum Materials, Chendi Xie

All Dissertations

This dissertation combines first-principles computation and light-induced nonequilibrium analysis to understand and control electron–phonon coupling (EPC) and emergent many-body phenomena in quantum materials, in both equilibrium and nonequilibrium states.

Chapters 1 and 2 build the theoretical and computational foundation, beginning with electron and phonon self-energies, linewidths, and perturbation theory for EPC, followed by density functional theory (DFT) and density functional perturbation theory (DFPT), which serve as the first-principles workhorses used throughout. Chapter 3 reviews Bardeen-Cooper-Schrieffer (BCS) and Migdal-Eliashberg theory, including the BCS gap - transition temperature (T_c) relation and the strong-coupling generalization, and delineates the practical validity bound …

Effects Of Radiation Type On Charge Transport In Aged Polymers, Zachary J. Gibson, Jr Dennison, Virginie Griseri

Journal Articles

Spacecraft charging issues are often investigated with simulated space environments and evaluated on pass–fail criteria that may yield little or no information about materials’ properties. It is far more effective to understand and mitigate spacecraft charging issues through investigations of material properties. However, material properties are dynamic in the harsh environment of space. Approximations must be made to simulate the space environment in the laboratory. This article reports on the investigation of the approximation that energy deposition causes the same aging effects in materials irrespective of the type of radiation sources. Samples of polytetrafluoroethylene (PTFE) and polyether-etherketone (PEEK) were irradiated …

Effect Of Space Radiation On The Mechanical Properties Of High-Strength Polyethylene Nanocomposite Films, Seunghyun Moon, Achal Duhoon, Zhongtian Gu, Jr Dennison, Tengfei Luo

Journal Articles

This study experimentally investigates the effects of prolonged radiation exposure on mechanical properties of high-strength, highly crystalline polyethylene (PE)/thermally reduced graphene oxide (TrGO) nanocomposite films for space applications. Prior to irradiation, PE/TrGO films were found to have tensile strengths up to ~4 GPa, more than 40 times that of conventional space-deployed membrane films (e.g., those used in solar sails) and over 59× the specific tensile strength. The PE/TrGO films were subjected to three radiation conditions to simulate space environmental conditions: ⁹⁰Sr beta radiation (0.2 to 2.5 MeV), 80 keV electron beam irradiation, and 4.9 eV ultraviolet (254 nm) exposure. …

Exploratory Study Of Semiconductor Nanomembranes In Em Applications, Grant D. Heileman

Electrical and Computer Engineering ETDs

Antenna systems are a cornerstone of modern technologies, playing an increasingly vital role in their advancement. As demand for compact, high-performance, and adaptable communication platforms grows reconfigurable antenna technologies are becoming essential. This research explores a novel front-end reconfigurable antenna system (FERAS) architecture that leverages the mechanical flexibility and photoconductive behavior of semiconductor nanomembrane (SNM) devices. By exploiting the emergent properties of ultra-thin silicon (Si) or gallium arsenide (GaAs) nanomaterials and optically exciting these samples using vertical-cavity surface-emitting laser (VCSEL) arrays, this study develops lightweight, low-cost, deployable antenna structures for satellite communications, remote sensing, GPS, and radar. Despite their significant …

Properties Of Liquid Fe-Ni Alloys Under Planetary Core Conditions And Their Geophysical Implications, Sajin Satyal

LSU Doctoral Dissertations

The composition of Earth’s core remains unsolved, yet it carries critical implications for planetary evolution, thermal history, magnetic fields, and habitability. Planetary models derived from seismological observations, such as the Preliminary Reference Earth Model (PREM), indicate that Earth’s core is significantly less dense than pure iron, implying the presence of light elements, including sulfur, carbon, hydrogen, oxygen, and silicon. However, the exact composition and distribution of these elements remain largely unknown. In constraining Earth’s core composition, the density and compressional wave velocity of iron-rich alloys are often compared with seismologically derived models. However, no single iron–light-element alloy can simultaneously reproduce …

Non-Reciprocal Coupling Of Minimal Active Colloids Under Confinement: Rotating Ferromagnetic Janus Particles Near Boundaries, Amrutha Raghu

LSU Doctoral Dissertations

Active colloids are microscopic particles that convert energy at the single-particle level into sustained motion and dynamically evolving assemblies. Their ability to transform continuous energy input into controlled motion opens new frontiers in microrobotics, adaptive materials, and targeted transport. Yet, achieving efficient propulsion at the microscale remains fundamentally challenging because viscous forces dominate while inertia becomes negligible. Unlike macroscopic systems that sustain propulsion through momentum, active colloids must harness non-reciprocal interactions with the surrounding fluid to generate persistent, time-irreversible motion. Studying minimal active systems—the simplest realizations that still capture the essential physics—provides a powerful route to uncover the non-equilibrium principles …

Universal Crackling Noise Links Plasticity In Nanoindentation With Compression In Metallic Glasses, Jordan Sickle, Wesley H. Higgins, Kerry A. Baker, Mayisha Nakib, Xiaojun Gu, George M. Pharr, Wendelin Wright, Karin A. Dahmen

Faculty Journal Articles

For decades, compression tests have been a standard method for identifying materials properties. However, these tests are slow, destructive, and require fabricating multiple potentially expensive bulk samples. Nanoindentation is fast, almost non-destructive, and requires only a single sample, to which large numbers of indents can be applied. Furthermore, nanoindentation is widely applicable, even to materials that are too brittle for traditional compression tests. Here, we show that nanoindentation is sufficient for extracting much of the same information that is measured in traditional sample compression tests in metallic glasses. The dynamics and statistics of the plasticity of two types of metallic …

Harnessing Coherent-Wave Control For Sensing Applications, Pablo Jara, Arthur Goetschy, Hui Cao, Alexey Yamilov

Physics Faculty Research & Creative Works

Imaging techniques such as functional near-infrared spectroscopy and diffuse optical tomography (DOT) achieve deep, noninvasive sensing in turbid media; however, they are constrained by the photon budget, as most of the injected light is lost to scattering before reaching the detector. Wavefront shaping (WFS) can enhance signal strength via interference at specific locations within scattering media, enhancing light-matter interactions and potentially extending the penetration depth of these techniques. Interpretation of the resulting measurements relies on knowing the optical sensitivity - the relationship between changes in the detected signals and perturbations at a specific location inside the medium; however, conventional diffusion-based …

Electron Yields Of Lunar Regolith Simulant Layers, Christopher Vega, Matthew Robertson, Thomas Keaton, Heather Allen, Jr Dennison

Journal Articles

The charging of bulk lunar regolith has been recognized since the Apollo era as an immediate and critical issue facing our return to the moon. Accurate electron yield (EY) measurements of bulk highly insulating granular materials—which largely determine how such particles charge through interactions with space environments—are lacking due to many experimental complexities that have led to a critical knowledge gap. Such knowledge is essential for addressing fundamental science and myriad important lunar applications and simulations related to lunar dust and regolith electrostatic charging. The few prior EY studies of lunar dust were limited due to severe charging effects and …

Time-Dependent Radiation Induced Conductivity Of Polyimide: Effects Of Dose Rate And Temperature On Dynamic Ric, Tyler Heggenes, Jenny R. Whiteley, Jodie Gillespie, Jr Dennison

Journal Articles

Radiation induced conductivity (RIC) can impact charge dissipation within highly insulating materials used in spacecraft in harsh space plasma environments. Previous Utah State University (USU) research analyzed only the equilibrium portions of an extensive RIC database for polymeric materials, including Kapton HN (Trademark). This confirmed that equilibrium RIC follows a standard theoretical model that is temperature and dose rate dependent. The current study provides a new analysis of RIC’s time-dependent behavior of the Kapton HN data from this database. With the onset of radiation, the material response is characterized by an exponential increase in conductivity, while a hyperbolic inverse time-dependent …

Unified Study Of The Classical Hall Effect, Carter J. Reed, Javier E. Hasbun, Wyatt E. Ackerman, L Ajith Desilva

Georgia Journal of Science

Germanium (Ge) samples with different doping types, acceptors (p-type) and donors (n-type), were studied to investigate charge carrier behavior. Carrier concentrations were found to be 1.16×10^21 m^(-3) for the p-type sample and 7.337×10^20 m^(-3) for the n-type sample. These experiments were conducted for the standard Hall effect (Hall voltage versus low magnetic field (B) values) as well as conductivity and Hall voltage versus temperature for different B-fields. The measurements versus temperature at zero-field allow us to obtain band gap ( Eg). While we investigate the conductivities for n-type and p-type doped samples, we also study the conductivity of an undoped …

A Theoretical Investigation Of Photo-Induced Deformations And Transitions In Nanoscale Ferroelectrics, Carmel Dansou

Graduate Theses and Dissertations

This dissertation presents a comprehensive first-principles investigation into the interaction of light with ferroelectric materials, focusing on light-induced structural responses (photostriction) and phase transitions in Ferroelectric superlattices, epitaxially strained BiFeO3 thin films, and twodimensional NbOX2 (X = Cl, Br, I) ferroelectrics. The work aims to provide microscopic insights into how light can control the lattice structure and even the crystallographic phase in these systems, with the broader goal of informing the design of light-responsive functional materials for practical technological applications. The first part explores light-induced effects in PbTiO3/SrTiO3 superlattices with different polarization orientations. Our simulations reveal that photoexcitation modifies the …

Synthesis And Properties Study Of Layered Magnetic Topological Materials, Gokul Acharya

Graduate Theses and Dissertations

The discovery of topological materials (TMs) has opened up exciting opportunities for probing fundamental physics and enhancing innovative device integrations. These materials display various exotic properties, such as large magnetoresistance, high mobility, chiral anomaly, and surface Fermi arcs. The magnetic versions of ZrSiS family, LnSbTe and LnPS (Ln = lanthanide) have attracted intensive attention as these materials provide a new platform to study interplay between magnetism, topological states, and electron correlations. The vast pool of topological materials has provided exciting avenues to precisely engineer the topological states by modulating spin-orbital coupling, electronic dimensionality, and lattice constant through element substitutions. This …

Ab Initio Studies On Mechanical Properties Of Freestanding Ferroic Monolayers, John Malcolm Davis

Graduate Theses and Dissertations

This thesis explores the role of mechanical properties and elastic couplings in freestanding paradigmatic ferroic monolayers within the framework of density functional theory. This dissertation is comprised of three interconnected published studies: (i) establishing the elastic behavior across a temperature-driven phase transition in SnSe monolayers; (ii) thermally-driven phase transitions in graphene-like silicene, germanene, and stanene, examining the structural stability and band gap occlusion; and (iii) magnetoelastic coupling in an Ising-like CrSiTe3 monolayer, focused on assessing magnetic contributions to the material stiffness by establishing a proper non-magnetic reference.

Nonlinear Diffusion, Hydrodynamic Cascades And Jamming In Kinetically Constrained Systems: Insights From Lattice Gas Models, Abhishek Raj

Dissertations, Theses, and Capstone Projects

This dissertation investigates non-linear diffusion processes and emergent dynamical phenomena in kinetically constrained lattice gases. Two central models are considered: a one-dimensional lattice gas exhibiting a diffusion cascade triggered by hydrodynamic nonlinearities and a triangular ladder exclusion model that undergoes a jamming transition. The former demonstrates stretched exponential decay consistent with non-perturbative long-time tails, while the latter illustrates how classical-quantum mappings yield insight into glassy dynamics and mobility constraints. Through a combination of numerical simulations, analytical perturbation theory, and mean-field approximations, the work uncovers mechanisms underlying anomalous transport, jamming transitions, and the breakdown of perturbative hydrodynamics.

Nonlinear Optics Through Femtosecond Light-Matter Interactions, Shah Faisal B. Mazhar

Dissertations, Theses, and Capstone Projects

This dissertation offers experimental and theoretical insights into nonlinear light-matter interactions induced by intense femtosecond (fs) laser pulses. It investigates key phenomena, including stimulated Raman scattering (SRS) from phonon and magnon quasiparticles, supercontinuum (SC) generation via self-phase modulation (SPM), conical emission (CE) arising from four-wave mixing (4WM), and modulation instability (MI) driven by cross-phase modulation (XPM) between SRS and SC processes. These effects are studied in diverse media using state-of-the-art femtosecond lasers.

The interplay among SRS, SC, 4WM, and MI is examined to probe vibrational modes and temperature-dependent magnetic excitations in condensed-matter systems. Experiments are conducted on anisotropic uniaxial calcite …

Multi-Nuclear Magnetic Resonance (Nmr) Characterization Of Novel Materials, Tawhid Pranto

Dissertations, Theses, and Capstone Projects

The increasing reliance on batteries in commercial products, coupled with the environmental challenges posed by climate change and the limitations of fossil fuel consumption, has created strong financial and environmental incentives to explore innovative energy storage solutions. Renewable energy sources are being actively developed, but their intermittent nature necessitates efficient storage technologies, driving significant research into improving the performance of batteries, fuel cells, and capacitors.

This thesis focuses on the application of advanced Nuclear Magnetic Resonance (NMR) spectroscopy to study and understand novel materials for energy storage applications, with an emphasis on electrolytes for rechargeable lithium-ion batteries and all-solid-state batteries. …

Nuclear Magnetic Resonance Characterization For The Study Of Beyond Lithium-Ion Battery Electrolytes, Allen Zheng

Dissertations, Theses, and Capstone Projects

To achieve a sustainable future, key issues in the energy and construction sectors such as the transition from fossil fuels to renewable energy sources and recycling of waste construction materials must be addressed. While fossil fuels offer a high energy density source of quick, consistent energy, renewable energy sources such as wind, solar, and hydroelectric offer intermittent energy output, requiring energy storage systems to maintain steady energy availability for consumers. Lithium-ion batteries (LIBs) are widely used in consumer electronics, electric vehicles, and grid storage due to their high energy density, low self-discharge, and rechargeability. However, they are limited by high …

Developments In The Lithographic Engineering Of Bi2sr2cacu2o8+Delta Mesa Terahertz-Emitting Devices, Sarah Elghazoly

Dissertations, Theses, and Capstone Projects

Devices microfabricated from the high-temperature superconducting cuprate Bi₂Sr₂CaCu₂O_8+𝛿 (Bi-2212) are a promising source of coherent terahertz radiation within the ’terahertz gap’ (0.3- 1.5 THz). A current-biased mesa patterned into the surface of a single crystal will produce electromagnetic radiation in the terahertz regime due to the naturally occurring Josephson junctions formed by the stacks of superconducting cuprate oxide planes in the material separated by insulating BiO and SrO barrier layers. Previous research has shown that by fabricating these mesas such that the geometry supports resonant cavity Fabry-Perot modes, the junctions within the mesa …

Equilibration And Transport Of Binary Mixtures On Planar And Porous Nanomaterials, Andrew Torres

Electronic Theses and Dissertations

We present results of a Kinetic Monte Carlo investigation of the adsorption dynamics of binary gas mixtures on planar and porous sorbents, with a focus on identifying and characterizing kinetic processes involved in uptake evolution and how they influence equilibrium conditions. We also investigate varying thermodynamic simulation parameters such as interactions, alkane lengths, partial pressures and pore configurations to determine how they impact these kinetic processes as well as equilibrium properties. This study matters both for better understanding how kinetics and equilibrium are connected and for improving practical techniques in separation applications. For planar surfaces, weak species overshoot kinetic processes …

Self Spin-Orbit Torques, Ryan Greening

Electronic Theses and Dissertations

Spin–Orbit torques (SOTs) provide an energy-efficient pathway to control magnetization in nanoscale heterostructures. Recently, spin-orbit coupling within ferromagnets has been shown to generate self spin-orbit torques (SSOTs) on the magnetization itself. Previous work on self spin-orbit torques relies on thick ferromagnets with complicated film structures with chemical disorder or compositional gradients to generate inversion symmetry breaking. This dissertation advances experimental methodology and presents data on the quantification of self spin-orbit torques in magnetic thin films due to the spin-orbit coupling of standard 3d ferromagnets.

First, I develop an oblique-incidence magneto-optical Kerr effect (MOKE) technique that exploits a mirror-assisted double reflection …

Techno-Enviro-Economic Approach For Electrification Of Rural And Shrimp Farming Regional Development Of An Isolated Island In Indonesia By Utilizing Hybrid Renewable Energy Systems, Fiqih Akbar Wijaya, Mohammad Akita Indianto

Journal of Materials Exploration and Findings

One of the challenges in developing and archipelagic countries such as Indonesia is maintaining energy demand in rural and isolated areas due to difficulties in electrical distribution. For instance, in areas like Bawean Island, no additional electricity capacity has been introduced in the past year, leading to an unmet potential customer demand. One of the possible options is by utilizing Hybrid Renewable Energy Systems (HRES) that are integrated with existing fossil fuel-based energy systems to support the growing energy demand in the remote island. A case study in Bawean Island is conducted with the projected energy demand covers the energy …

Remaining Life Assessment And Fitness For Service Evaluation Of Aging Chemical Reactors In Polyethylene Terephthalate Resin Industry, Aditya Pahlawan Munthe, Donanta Dhaneswara, Wahyuaji Narottama Putra, Gama Widyaputra

Journal of Materials Exploration and Findings

Aging chemical reactors in the polyethylene terephthalate (PET) resin industry require comprehensive evaluation to ensure safe continued operation. This study conducts a remaining life assessment (RLA) and fitness-for-service (FFS) evaluation on five 30-year-old reactors, based on API 510, API 579/ASME FFS-1, and ASME BPVC Section VIII Div. 1 standards. The analysis involves corrosion rate measurement, future corrosion allowance (FCA) projection, and minimum thickness verification. Among the reactors, R-120 was found to have the shortest remaining life less than 15 years. FFS assessments using three criteria Average Measured Thickness, MAWP from Point Thickness Readings, and Minimum Measured Thickness confirm that R-120 …

A Study Of Wear Measurement And Life Prediction Of Insert Chute Liner On Gold Ore Processing, Ferry Ardika Natanael, Nony Maulidya, Dedi Priadi

Journal of Materials Exploration and Findings

Chutes are critical materials handling assets to transport solid particles from one process step to another in mineral processing, coal mining and cement industries. The material transport, because of material characteristics, cause severe wear on internal lining of chutes or bins’ structure. The wear problem on internal lining of bins or chutes needs to be checked to keep production efficiency. Therefore, not checked wear rate causes liner replacement schedule becomes unpredictable. It leads to production loss and highly cost maintenance in industry. This study shows that condition-based maintenance through regular thickness measurement using Ultrasonic Transducer (UT) to predict life service …

Analysis Of Leak Testing Planning For Carbon Dioxide Piping Systems In The Development Of Carbon Capture, Utilization, And Storage Facilities In The Bintuni Basin, Devi Sentiani, Akhmad Herman Yuwono Professor

Journal of Materials Exploration and Findings

Carbon Capture, Utilization, and Storage (CCUS) technologies have become a key strategic response to global efforts to reduce CO₂ emissions. This study presents a leak testing strategy designed for a carbon dioxide (CO₂) piping system as part of a Carbon Capture, Utilization, and Storage (CCUS) project in the Bintuni Basin, West Papua, Indonesia. This study aims to ensure the system is properly prepared before commissioning by designing a leak test plan that is both practical and technical, based on ASME B31.3, ASME PCC-2, and API STD 520 Part 1. We conducted the process, which involves identifying the system boundaries, …

Pylro: A Python Calculator For Analyzing Long-Range Structural Order, Kevin Parrish

UNLV Theses, Dissertations, Professional Papers, and Capstones

We present PyLRO, an open-source Python calculator designed to detect, quantify, and display long-range order in periodic structures. The program’s design methodology, workflow, and approach to order quantification are thoroughly described and demonstrated using a simple toy model. Great care is considered in the detailing of the calculation logic, as is standard in the development of computational methods. Additionally, we apply PyLRO to a series of metastable AlPO4 structural intermediates from a prior high-pressure study, demonstrating how to compute and visualize structural order in all directions on a Miller sphere. We further highlight the program’s capabilities through a high-throughput analysis …

Time-Evolved Constant Voltage Conductivity Measurements Of Common Spaceborne Polymeric Materials, Brian Wood, David King, Jr Dennison

Journal Articles

Long-duration current measurements were made for low-density polyethylene (LDPE), polyimide (PI), polyether ether ketone (PEEK), and biaxially oriented polypropylene (BOPP) to determine their bulk conductivity near room temperature as a function of time. These common thin-film spacecraft material samples were vacuum baked to remove moisture and volatile contaminants to better simulate space conditions. The constant voltage conductivity (CVC) method used a very stable, low-noise dc voltage source and measured the resulting current in a parallel plate geometry. Due to the extremely low conductivity of these four polymeric materials, extended experiments of up to ten days were necessary to establish equilibrium …

Low Energy Ion Irradiation Effects In Electronic Devices And Materials, David C. Mccall

All Dissertations

The physics and engineering of ion-solid interactions are governed by the ion beam characteristics (flux, charge, energy) and target(s) in question. Here I present work on two projects related to the extraction of a high flux of low charge state Argon ions from a commercial plasma source and the irradiation of an engineered target, a transistor, with high charge state Argon ions.

An end-Hall ion source that produces a a high current plasma of ions and electrons in a rough vacuum environment is characterized. Using a Langmuir probe and multiple pressure measurements, the ion and electron content of the source …