Physics Commons^™

Raman Scattering Measurements And Analyses Of Gan Thin Films Grown On Zno Substrates By Metalorganic Chemical Vapor Deposition, Zane Mcdaniel, Zhe Chuan Feng, Kevin Stokes

Symposium of Student Scholars

Metalorganic chemical vapor deposition (MOCVD) is a popularly used method of growing thin films of GaN on ZnO (GZ) substrates, which pair well due to their structural and characteristic similarities. In this research, optical characterization of the surface quality of GZ sample films is measured by analyzing Raman scattering (RS) using a Renishaw inVia spectrometer fitted with a 532nm laser. Samples were grown in an improved double injection block rotating disc reactor. Multiple samples' spectra show broad peaks that correspond with the E2 (high) and A1 (LO) branches of GaN, and nicely fitted curves are observed for the characteristic E2 …

Synthesis And Characterization Of Chiral Magnetic Oxide: Mnmoteo6, Chase Hames, August Meads

Symposium of Student Scholars

The chiral materials lack mirror reflection symmetry in their crystal structures like right and left hands. Such materials often host unique non-collinear or topological magnetic textures such as magnetic skyrmions. If such magnetic textures are formed in insulating oxides with coupled electric and magnetic properties, then such magnetic structures can be controlled and manipulated using electric fields rather than electric current. With this motivation, we are synthesizing and characterizing chiral materials belonging to MMoTeO₆ (M=Mn, Co, Fe, Cu, Ni) family. I will discuss about the phase formation and solid-state synthesis of MnTeMoO₆ along with its structural, electrical and …

High Speed Impact On Graphene Composites, Giovanny A. Espitia

Symposium of Student Scholars

Since the isolation of Graphene occurred in 2004, numerous studies attempting to exploit the properties of this carbon allotrope have been conducted. Graphene exists in a 2-D manner with sp2 bonds, which provides the allotrope with great electrical, conductive, and mechanical properties. In this paper however, we will focus on the latter in order to examine the feasibility of graphene composites for bulletproof material in the military. Pure graphene sheets count with high porosity density that leads to structural defects as well as poor mechanical properties due to physical contact being sole retainer. For this reason, the selected composite is …

Therapeautic Cerium Oxide Nanoparticles, Angel E. Vasquez

Symposium of Student Scholars

The overall goal of the research project is to create a glass that produces cerium oxide nanoparticles and as an efficient delivery mechanism. Cerium is able to exist as Ce3+ and Ce4+ because it has two partially filled subshells. This coexistence allows cerium oxide to have antioxidant properties that reduce the number of free radicals in that body that are associated with cancer, diabetes, and neurodegenerative diseases. In our laboratory, using a soluble borate glass, cerium oxide nanoparticles are created to coexist in Ce3+ and Ce4+ valences This borate glass composition is doped with different amounts of Cerium(IV) Oxide and …

Physical Properties Of Polar Magnetic Oxides Hofewo6

Symposium of Student Scholars

Polar magnetic oxides are interesting systems to study due to the possibility of hosting functional properties such as ferroelectricity, piezoelectricity, etc. In this work, a new compound HoFeWO₆ is synthesized using high-temperature solid-state reaction and characterized using x-ray diffraction, neutron diffraction, magnetization measurements, and dielectric measurements. The x-ray and neutron diffraction results indicate that HoFeWO₆ crystallizes in polar (non-centrosymmetric and achiral) orthorhombic structure P n a 21. The magnetization measurements indicate that HoFeWO₆ exhibit paramagnetic to antiferromagnetic transition at T_N = 18 K. The dielectric properties at room temperature indicate that the dielectric constant decreases with …

Solid State Synthesis Of Chiral Magnetic Alloys, Connor Quick

Symposium of Student Scholars

Solid State Synthesis of Chiral Magnetic Alloys

Connor Quick, Chetan Dhital

The cubic magnetic alloys such as MnSi, FeGe, and MnSi crystallize in non-centrosymmetric chiral crystal structure. Due to the combination of non-centrosymmetric structure and the magnetism, these magnetic alloys lead to the discovery of new type of magnetic configurations called magnetic skyrmion in certain temperature and field ranges. Such magnetic skyrmions are considered to provide energy efficient and high storage capacity alternatives to currently used domain wall based random access memory. There are two major problems in this field of research: (a) availability of limited number of materials (b) …

Solid State Synthesis Of Polar Magnetic Oxides, Duy Pham

Symposium of Student Scholars

Non-centrosymmetric polar oxides are subjects of considerable interest due to varieties of important phenomena and associated functional properties. Magnetoelectric multiferroic oxides are one such system where the magnetic properties can be controlled by electric field or the electric properties can be controlled by the magnetic field. This cross tunability magnetic and electrical properties makes multiferroic materials ideal candidates for making actuators, field sensors and memory devices. Simultaneous presence of broken inversion symmetry (electric polarization) and magnetism are two key requirements for multiferroicity. Non-centrosymmetric polar magnetic oxides simultaneously offer both (polarization and magnetization) properties. Therefore, we are working toward synthesis and …

Electrochemical And Spectroscopic Characterization Of Cerium Salts And Nanoceria Material, Emily Velarde, Wei Zhou

Symposium of Student Scholars

The nanoscale form of cerium oxide, nanoceria (nano-CeO_x), has drawn great attention in recent years in electrochemical, nanomaterial research and medicinal studies due to its antibacterial properties, UV absorption, and its biochemical function as possible radical scavenger. Many new synthesis methods have achieved uniform and biocompatible nanoceria particles, and our lab has created cerium oxide particles that shows UV/Vis. absorption and X-ray patterns similar to the commercial nanoceria and nanoceria made in other research laboratories with novel synthetic methods.

This study focuses on charactering and comparing electrochemical properties of cerium inorganic salts and synthesized nanoceria. Preliminary results …

Thermal Analysis Of Borosilicate Glass For Its Biological Applications, Gregory Humble

Symposium of Student Scholars

Borosilicate glass doped with varying wt% of cerium oxide is investigated for biological applications. Thermal studies of each formulation were conducted using an SDT Q600 differential scanning calorimeter. 30mg samples of 350 - 425 μm particle size of each type of glass were heated to 1200°C in order to obtain the glass transition, crystallization, and melting temperatures. Samples were then heated to 900°C at several heating rates, ranging from 2°C/min to 100°C/min, then compared against each other as well as against an undoped borosilicate glass.

Crystal Nucleation Of Palladium-Doped Lithium Disilicate Glass, Gregory Humble

Symposium of Student Scholars

The effect of concentration of palladium particles on crystal nucleation was investigated for lithium disilicate glass. The heterogeneous nucleation rate for 470°C and 480°C were calculated for a concentration of 0.001% palladium by weight. The DTA method of measuring nucleation and crystallization was used in this calculation.