Effect Of Reduction Annealing On The Structural And Electrical Properties Of Α-Moo3 Thin Films,
2025
Missouri State University
Effect Of Reduction Annealing On The Structural And Electrical Properties Of Α-Moo3 Thin Films, Sandipani Ghosh
Graduate Theses/Dissertations
2D layered molybdenum oxide has attracted significant research interest due to its tuneable bandgap and diverse structural, chemical, electrical, and optical properties influenced by growth parameters and synthesis techniques. In this study, the effects of reduction annealing on the structural and electrical properties of few-layer MoO₃ thin films, deposited on Si/SiO₂ substrates via pulsed laser deposition, were investigated. X-ray diffraction revealed nanocrystalline structures with a preferred (020) orientation, reduction annealing produced highly crystalline orthorhombic α-MoO₃ with reduced unit cell volume. FESEM/EDS provided detailed analyses of microstructures and elemental compositions. Raman spectroscopy confirmed the orthorhombic structure, with characteristic peaks at 667, …
Interactions And Applications Of Optical Angular Momentum In Magneto-Optical Material,
2025
Michigan Technological University
Interactions And Applications Of Optical Angular Momentum In Magneto-Optical Material, Seth R. Nelson
Dissertations, Master's Theses and Master's Reports
This dissertation explores the interactions and applications of optical angular momentum within magneto-optical materials. Beginning with a theoretical and experimental analysis of multiple reflection and refraction phenomena within magneto-optical material. We derive and verify the dependence of refractive indices on optical spin angular momentum and magneto-optical magnetization, resulting in nonreciprocal elliptical and linear polarization beam splitting effects and wavevector discretization. We fabricate a magnetless slab waveguide isolator with minimal optical loss. Extending our study to optical orbital angular momentum, we introduce a perturbation to the electronic transition model in bismuth-substituted iron garnets. We demonstrate that this perturbation leads to nonreciprocal …
Formation Of Pyramidal Palladium Enhanced By B(C₆F₅)₃ Additive Enabling Selective Alkene Monoisomerization,
2025
Old Dominion University
Formation Of Pyramidal Palladium Enhanced By B(C₆F₅)₃ Additive Enabling Selective Alkene Monoisomerization, Paul D. Miller, Trandon A. Bender
Chemistry & Biochemistry Faculty Publications
The addition of a strong Lewis acid, tris(pentafluorophenyl)borane, facilitates the reduction of Pd(cod)Cl₂ with Et₃SiH to form palladium nanoparticles in organic solvents. It was found that these palladium nanoparticles are capable of selective monoisomerization of linear alkenes. This heterogeneous palladium catalyst is tolerant of a wide variety of functional groups, confirmed by substrate and robustness screenings. It is also possible to utilize poly(methylhydro)siloxane, an industrial waste byproduct, as the reductant to enable similar isomerization chemistry.
Periodic Trends In The Electronic And Magnetic Structure Of Superatomic 3d Transition Metal Chalcogenide Clusters,
2025
Virginia Commonwealth University
Periodic Trends In The Electronic And Magnetic Structure Of Superatomic 3d Transition Metal Chalcogenide Clusters, Gabriel Bohannon
Theses and Dissertations
We have systematically investigated the electronic structure of octahedral transition metal chalcogenide clusters, TM6S8(CO)6, in which the transition metal atoms are from the 3d series in order to identify if periodic properties emerge. We were motivated by the identification of closed electronic shells with electron counts of 96, 100 and 114 in similar clusters from the 4d and 5d transition metal series. Further motivation was the finding of a dual-shell closing in the Fe6S8(CN)65- cluster. This cluster is stabilized with a large spin magnetic moment due to the …
Applying The Lagrangian Variational Method To Atom Interferometry,
2025
Georgia Southern University
Applying The Lagrangian Variational Method To Atom Interferometry, Jeffrey W. Heward
College of Graduate Studies: Theses & Dissertations
Atom interferometry in Bose-Einstein condensate systems has emerged as a promising technique for precision metrology. The dynamics of these systems are well-described by the Gross-Pitaevskii equation (GPE), but direct numerical solution of this equation is infeasible for realistic systems. We use the Lagrangian Variational Method (LVM) to approximate solutions of the GPE in 1D and 3D, and we compare the LVM results to the exact solutions. We also present 3D LVM results for a case where numerical solution of the GPE is infeasible.
Synthesis And Characterization Of Doped Rare-Earth Zinc Alloys,
2025
Missouri State University
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 …
Photoionization Of Spin-Polarized Rydberg Atoms Out Of A Continuous Wave Optical Dipole Trap,
2025
Missouri University of Science and Technology
Photoionization Of Spin-Polarized Rydberg Atoms Out Of A Continuous Wave Optical Dipole Trap, Kevin Lee Romans
Doctoral Dissertations
"Recent research has demonstrated the need for a fully differential experiment on the photoionization of 6Li Rydberg atoms in a continuous wave (cw) laser field, as this would provide a new path forward for studying never before accessible atom-light interactions. Rydberg atoms are back in the focus of intense research due to their peculiar properties, which make them interesting candidates for quantum optics and information applications. In this work, we study the ionization of such Rydberg atoms, due to their interaction with a trapping laser field, by utilizing a reaction microscope (ReMi) capable of measuring photoelectron momentum distributions with …
Reconstructing Superoscillations Buried Deeply In Noise,
2024
Chapman University
Reconstructing Superoscillations Buried Deeply In Noise, Derek D. White, Shunxing Zhang, Barbara Šoda, Achim Kempf, Daniele C. Struppa, Andrew N. Jordan, John C. Howell
Mathematics, Physics, and Computer Science Faculty Articles and Research
We utilize a method using frequency combs to construct waves that feature superoscillations—local regions of the wave that exhibit a change in phase that the bandlimits of the wave should not otherwise allow. This method has been shown to create superoscillating regions that mimic any analytic function—even ones well outside the bandlimits—to an arbitrary degree of accuracy. We experimentally demonstrate that these waves are extremely robust against noise, allowing for accurate reconstruction of a superoscillating target function thoroughly buried in noise. We additionally show that such a construction can be easily used to range-resolve a signal well below the commonly …
Modeling Of Light Filamentation For Nonlinear Imaging And Waveguiding,
2024
Southern Methodist University
Modeling Of Light Filamentation For Nonlinear Imaging And Waveguiding, Nicholas Bagley
Mathematics Theses and Dissertations
Ultrashort pulses are capable of extremely high powers; in addition to enabling various applications in defense, sensing, and imaging, they provide a useful arena in which to study nonlinear optical phenomena that are observable only at high intensities. Due to these effects, which can include ionization and thermal blooming, simulation of ultrashort pulse propagation is a complicated multiphysics problem. We provide an overview of techniques used to simulate the propagation of ultrashort pulses in the nonlinear regime, including the formation of light filaments due to the competition of Kerr self-focusing and defocusing (e.g. via plasma generation). We discuss both carrier-resolved …
Effect Of Temperature And Rhenium Content In Precipitates On Dispersion Hardening Of Tungsten,
2024
Research Laboratory for Metals and Alloys under Extreme Impacts, Ufa University of Science and Technology, Ufa, Russia;
Effect Of Temperature And Rhenium Content In Precipitates On Dispersion Hardening Of Tungsten, Yulia R. Sharapova, Arseny M. Kazakov, Elena A. Korznikova, Alexandr Zinovev, Dmitry Terentyev, Sergey V. Dmitriev
Karbala International Journal of Modern Science
Tungsten (W) is being developed as a plasma-facing material for fusion reactors, where it is subjected to MeV neutron irradiation, low-energy helium isotope particles, and high temperatures. These conditions lead to the formation of point defects, dislocation loops, voids, and transmutation into rhenium (Re) and osmium (Os), which form precipitates that significantly impact dislocation motion and increase hardness. This study uses molecular dynamics modeling to examine the interaction between an edge dislocation and Re-rich particles of various stoichiometries, specifically coherent bcc-phase particles and noncoherent σ-phase precipitates. Results show that shear stress increases by approximately 20-40% with larger particle size (3-5 …
Beamed: A Bench For Automated Measurements Of Electrical Discharges - A New Standard For Paschen Curves,
2024
Embry-Riddle Aeronautical University
Beamed: A Bench For Automated Measurements Of Electrical Discharges - A New Standard For Paschen Curves, Jared Nelson
Doctoral Dissertations and Master's Theses
The initiation of electrical discharges, particularly glow discharges, plays a significant role in industry and environmental science, affecting systems such as electronics, power grids, and atmospheric phenomena. Despite extensive studies and applications of Paschen's law, current methodologies for experimental Paschen tests in direct current (DC) conditions lack standardized practices. This thesis presents the development and validation of a DC-based standard for electrical discharge initiation, using the BEnch for Automated Measurements of Electrical Discharges (BeAMED). BeAMED is designed to standardize the experimental process by automating electrical discharges' initiation and data acquisition. The autonomous nature of the system provides insights into the …
Characterizing 2d Materials Using Positron Impact Induced Electron Spectroscopy And Development Of A Novel Thin Film Zno Based Piezo-Photonic Detector For Cryogenic And Mems Applications,
2024
University of Texas at Arlington
Characterizing 2d Materials Using Positron Impact Induced Electron Spectroscopy And Development Of A Novel Thin Film Zno Based Piezo-Photonic Detector For Cryogenic And Mems Applications, Pratyanik Sau
2024 Fall Honors Capstone Projects - Archive
Surface analytical techniques are essential for engineering nano-detectors allowing characterization of their chemical composition, electromechanical properties, and physical structure. In the first chapter, the positron impact-induced secondary electron (PIISE) energy spectra and yield from single-layer graphene (SLG) and multi-layer graphene (MLG) grown on a polycrystalline Cu substrate have been presented. In the second chapter, an extensive catalog of Positron Induced Auger Spectra is presented to aid in the analysis of elemental composition of various materials. Additionally, in the third chapter, a novel detection scheme utilizing the piezo-pyroelectric properties of Zinc Oxide (ZnO) thin films have been demonstrated for its application …
Graphene-Based Antennas Utilizing Polyvinylidene Fluoride (Pvdf) Substrates For Attenuation,
2024
University of Arkansas, Fayetteville
Graphene-Based Antennas Utilizing Polyvinylidene Fluoride (Pvdf) Substrates For Attenuation, Josef Frankhouse
Mechanical Engineering Undergraduate Honors Theses
In this study, a Terahertz (THz) band antenna which can regulate its own resonant frequency without the requirement of manual adjustment is simulated. A polyvinylidene fluoride (PVDF) substrate is applied onto a rectangular graphene patch antenna. With a voltage potential applied onto the PVDF, the patch antenna can attenuate its frequency by physically changing the shape of the antenna, and in turn its resonant frequency. These antennas are within a 0.1 THz band between 1.32 THz to 1.22 THz measured from a radial bend of a flat surface to r = 75 , fitting into a return loss (S11 …
A Simple And Low-Cost Method For Generating Short Laser Pulses,
2024
University of Nevada, Las Vegas
A Simple And Low-Cost Method For Generating Short Laser Pulses, Daniel Fisher
Undergraduate Research Symposium Posters
A simple, portable method is described and demonstrated for generating short optical pulses (~ 1 μsec) from a continuous wave (CW) source using a rotating pinhole. A CW 633nm HeNe beam was focused onto a 225 μm diameter stainless steel pinhole, which was rotated up to 1000 Hz using an optical chopper wheel. The pulsed light was then focused onto a silicon photodetector and read by an oscilloscope. This novel setup aims to bridge the gap between pulsed laser performance and price for wide application in spectroscopy methods, industrial laser peening, and medical treatments. This will be the first publication …
Computational Design Of Complex Concentrated Alloys,
2024
Louisiana Tech University
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 …
Scalable Methods For Performant Control Of Hyperfine Qubits In Atoms And Ions,
2024
University of New Mexico; Center for Quantum Information and Control; Sandia National Laboratories
Scalable Methods For Performant Control Of Hyperfine Qubits In Atoms And Ions, Matthew N. H. Chow
Physics & Astronomy ETDs
Qubits encoded within internal energy levels of atoms and ions have been used to demonstrate high-performance primitives of quantum computing for small numbers of qubits. Yet, the path to achieving sufficient size and fidelity for useful fault-tolerant quantum computation remains daunting. In this dissertation, I present several techniques I developed as steps along this path. These results include high-fidelity, low-loss detection for alkali atoms in optical tweezers, crosstalk-mitigated parallel one-qubit gates, robust entangling gates on trapped ions, and leakage-to-erasure conversion for non-destructive detection of atom loss errors. Through this collection of techniques, I have sought to make full use of …
Quantum Many-Body Scars In Few-Body Dipole-Dipole Interactions,
2024
Bryn Mawr College
Quantum Many-Body Scars In Few-Body Dipole-Dipole Interactions, Sarah E. Spielman, Alicia Handian, Nina P. Inman, Thomas J. Carroll, Michael W. Noel
Physics and Astronomy Faculty Publications
We simulate the dynamics of Rydberg atoms resonantly exchanging energy via two-, three-, and four-body dipole-dipole interactions in a one-dimensional array. Using simplified models of a realistic experimental system, we study the initial-state survival probability, mean level spacing, spread of entanglement, and properties of the energy eigenstates. By exploring a range of disorders and interaction strengths, we find regions in parameter space where the three- and four-body dynamics either fail to thermalize or do so slowly. The interplay between the stronger hopping and weaker field-tuned interactions gives rise to quantum many-body scar states, which play a critical role in slowing …
Experimental Characterization, Computational Investigation, And Structure-Property–Activity Relationship Studies Of Nickel Ferrite Nanostructures,
2024
University of Sfax, Faculty of Science of Sfax, Laboratory of Applied Physic, Sfax 3018 Tunisia
Experimental Characterization, Computational Investigation, And Structure-Property–Activity Relationship Studies Of Nickel Ferrite Nanostructures, Ali Ben Ahmed
Polytechnic Journal
Intending to predict the multifunctionality of Nickel ferrite in several technological and medical fields, we have prepared nickel ferrite nanostructure by coprecipitation method. X-ray Diffraction (XRD) is used to determine the crystalline structure and phase composition of materials by analyzing the pattern of X-rays scattered by the atoms within the material. Fourier Transform Infrared Spectroscopy (FTIR) provides information about a material's chemical bonds and functional groups by analyzing how it absorbs infrared light at various wavelengths. Scanning Electron Microscopy (SEM) offers high-resolution images of the material's surface morphology and texture by scanning it with a focused beam of electrons. Transmission …
Super-Resolution Magnetic Microscopy And Earth’S Field Magnetometry With Color Centers In Diamond,
2024
University of New Mexico
Super-Resolution Magnetic Microscopy And Earth’S Field Magnetometry With Color Centers In Diamond, Nazanin Mosavian
Optical Science and Engineering ETDs
In recent years, the negatively charged nitrogen- vacancy (NV) center has emerged as a promising solid-state color center capable of measuring magnetic fields with high sensi- tivity and spatial resolution under ambient conditions. In this thesis I will discuss how we perform super resolution magnetic microscopy and acquire magnetic field images of nanoparticle samples at 100 nm resolution. I will explain how 3D flux concentrators increase magnetic field amplitude and allows us to measure vector component magnetic fields as low as 50 µT with a diamond magnetometer, without the use of an additional bias magnetic field. I also describe how …
Wavefront Sensor Based On Angle Selectivity Of An Optical Filter,
2024
Fraunhofer Institute of Optronics, System Technologies and Image Exploitation
Wavefront Sensor Based On Angle Selectivity Of An Optical Filter, Andreas Zepp, Emma Branigan, Julien Garnier, Kevin Murphy, Raphael Bellossi, Karin Stein, Szymon Gladysz
Conference Papers
The effectiveness of free-space laser communications is limited due to wavefront deformations caused by atmospheric optical turbulence. To determine these deformations, we propose a wavefront sensor that utilizes the angular selectivity of an optical transmission filter to measure the first derivative of the wavefront. The transmission filter converts the gradients of the incident wavefront into an intensity distribution. For each direction (x and y) this distribution is captured twice, with different angles between filter and optical axis for each measurement. The contrast of both measurements (calculated for each pixel of the used detector) and the local gradients of the wavefront …
