The Effects Of Tilted Magnetic Fields On Quantum Transport In 2d Electron Systems,
2017
CUNY Graduate Center
The Effects Of Tilted Magnetic Fields On Quantum Transport In 2d Electron Systems, William A. Mayer
Dissertations, Theses, and Capstone Projects
There exists a myriad of quantum transport phenomena in highly mobile 2D electrons placed in a perpendicular magnetic field. We study the effects of tilted magnetic field on these transport properties to understand how the energy spectrum evolves. We observe significant changes of the electron transport in quantum wells of varying widths with high electron densities at high filling factors. In narrow quantum wells the spin splitting of Landau levels due to Zeeman effect is found to be the dominant mechanism reducing Quantum Positive Magnetoresistance. In wider quantum wells with two populated subbands Magnetointersubband oscillations appear to exhibit effects from …
Structure And Physical Properties Of Srniru5O11 Single Crystals: An R-Type Ferrite Based On Ordered Kagome Nets,
2017
Universität Stuttgart, Germany
Structure And Physical Properties Of Srniru5O11 Single Crystals: An R-Type Ferrite Based On Ordered Kagome Nets, L. Shlyk, Lance E. De Long, R. Niewa
Physics and Astronomy Faculty Publications
Single crystals of the R-type ferrite SrNiRu5O11 were grown from a chloride flux. The hexagonal crystal structure contains ruthenium located on distorted kagome nets. The low-temperature dc magnetic susceptibilities (χ⊥ and χ∥, perpendicular and parallel to the c axis, respectively) diverge as T−0.3, and do not exhibit any indication of long-range magnetic order down to 4.5 K. The electrical resistivity varies as T1.6 below 40 K, which is typical of non-Fermi liquids, and may originate from a competition between residual magnetic interactions among Ni2+ (S = 1) spins …
How The Space Environment Affects Seed Germination And Growth,
2017
Utah State University
How The Space Environment Affects Seed Germination And Growth, Alexander Souvall, Gareema Dhiman, Andre Nguyen, Michelle Jung, Astrid Ji, Takayuki Sakai, Takahiro Shimizu, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Shaunda Wenger, Toshihiro Kameda, Jr Dennison
Posters
Understanding observed space environment effects on biological organisms such seeds are important in design of long duration space missions, such as to those planned for Mars, where appropriate storage and growth of food resources is essential. Evaluation of the effects of the real and simulated space environment on seed germination and growth in space is the purpose of this research. Preliminary tests of germination rate and growth of radish seeds in a controlled environment have identified statistically significant differences between control samples and seeds flown for 30 days in low earth orbit on the Bion M-1 launch capsule Russian research …
Microcontroller And Memory Card Survivability In Space Conditions,
2017
Utah State University
Microcontroller And Memory Card Survivability In Space Conditions, Windy Olsen
Senior Theses and Projects
No abstract provided.
Relaxation Of Charge In Monolayer Graphene: Fast Nonlinear Diffusion Versus Coulomb Effects,
2017
University of Virginia
Relaxation Of Charge In Monolayer Graphene: Fast Nonlinear Diffusion Versus Coulomb Effects, Eugene B. Kolomeisky, Joseph P. Straley
Physics and Astronomy Faculty Publications
Pristine monolayer graphene exhibits very poor screening because the density of states vanishes at the Dirac point. As a result, charge relaxation is controlled by the effects of zero-point motion (rather than by the Coulomb interaction) over a wide range of parameters. Combined with the fact that graphene possesses finite intrinsic conductivity, this leads to a regime of relaxation described by a nonlinear diffusion equation with a diffusion coefficient that diverges at zero charge density. Some consequences of this fast diffusion are self-similar superdiffusive regimes of relaxation, the development of a charge depleted region at the interface between electron- and …
Doping Evolution Of Magnetic Order And Magnetic Excitations In (Sr1-XLaX)3Ir2O7,
2017
Paul Scherrer Institut, Switzerland
Doping Evolution Of Magnetic Order And Magnetic Excitations In (Sr1-XLaX)3Ir2O7, Xingye Lu, D. E. Mcnally, M. Moretti Sala, Jsaminka Terzic, M. H. Upton, D. Casa, G. Ingold, Gang Cao, T. Schmitt
Physics and Astronomy Faculty Publications
We use resonant elastic and inelastic x-ray scattering at the Ir-L3 edge to study the doping-dependent magnetic order, magnetic excitations, and spin-orbit excitons in the electron-doped bilayer iridate (Sr1−xLax)3Ir2O7 (0 ≤ x ≤ 0.065). With increasing doping x, the three-dimensional long range antiferromagnetic order is gradually suppressed and evolves into a three-dimensional short range order across the insulator-to-metal transition from x = 0 to 0.05, followed by a transition to two-dimensional short range order between x = 0.05 and 0.065. Because of the interactions between the J …
Epitaxial Strain Controlled Magnetocrystalline Anisotropy In Ultrathin Ferh/Mgo Bilayers,
2017
Tongji University & California State University
Epitaxial Strain Controlled Magnetocrystalline Anisotropy In Ultrathin Ferh/Mgo Bilayers, Guohul Zheng, San-Huang Ke, Maosheng Miao, Jinwoong Kim, R, Ramesh, Nicholas Kioussis
Nebraska Center for Materials and Nanoscience: Faculty Publications
Using ab initio electronic structure calculations we have investigated the effect of epitazial strain on the magnetocrystalline anisotropy (MCA) of ultrathin FeRh/MgO heterostructures. Analysis of the energy- and k-resolved distribution of the orbital character of the band structure reveals that MCA largely arises from the spin-orbit coupling (SOC) between dx2-y2 and dxz/dyz orbitlas of Fe atoms at the FeRh/MhO interface. We demonstrate that the strain has significant effects on the MCA: It not only affects the value of the MCA but also induces a switching of the magnetic easy axis from perpendicular on in-plane direction. The …
Effects Of Space Travel On Seed Germination And Viability,
2017
Logan High School
Effects Of Space Travel On Seed Germination And Viability, Greema Dhiman, Michelle Jung, Andre Nguyen, Shaunda Wenger, Alexander Souvall, Jr Dennison, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Toshihiro Kameda
Posters
No abstract provided.
First-Principle Investigation Of Structural, Electronic And Magnetic Properties Of Co2vin And Covin Heusler Compounds,
2017
University of Nairobi
First-Principle Investigation Of Structural, Electronic And Magnetic Properties Of Co2vin And Covin Heusler Compounds, Zipporah Muthui, Rohit Pathak, Robinson Musembi, Julius Mwabora, Ralph Skomski, Arti Kashyap
Nebraska Center for Materials and Nanoscience: Faculty Publications
Investigation of the structural, electronic and magnetic properties of full-Heusler Co2VIn as well as half-Heusler CoVIn Cobalt based Heusler compounds using density functional theory (DFT) leads to the general conclusion that Co2VIn and CoVIn are half-metallic materials with a gap at the Fermi level in the minority states and majority states respectively. A Hubbard-like Coulomb correlation term U has been included in the DFT (DFT+U) for the computation of the electronic and magnetic properties of the compounds. The structural properties have been calculated for the paramagnetic and ferromagnetic phases, and both Co2VIn …
Controlling The Microstructure And Associated Magnetic Properties Of Ni0.2mn3.2ga0.6 Melt-Spun Ribbons By
Annealing,
2017
Miami University - Oxford
Controlling The Microstructure And Associated Magnetic Properties Of Ni0.2mn3.2ga0.6 Melt-Spun Ribbons By Annealing, Mahmud Khan, Ohud Alshammari, Balamurugan Balamurugan, Bhaskar Das, David J. Sellmyer, Ahmad Us Saleheen, Shane Stadler
Nebraska Center for Materials and Nanoscience: Faculty Publications
Here we report on the structural and magnetic properties of Ni0.2Mn3.2Ga0.6 melt- spun ribbons. The as-spun ribbons were found to exhibit mixed cubic phases that transform to non-cubic structure upon annealing. Additionally, an amorphous phase was found to co-exist in all ribbons. The SEM images show that minor grain forma- tion occurs on the as-spun ribbons. However, the formation of extensive nano-grains was observed on the surfaces of the annealed ribbons. While the as-spun ribbons exhibit predominantly paramagnetic behavior, the ribbons annealed under various thermal conditions were found to be ferromagnetic with a Curie temperature …
Effect Of Fe Substitution On The Structural, Magnetic And Electron-Transport Properties Of Half-Metallic Co2tisi,
2017
University of Nebraska - Lincoln
Effect Of Fe Substitution On The Structural, Magnetic And Electron-Transport Properties Of Half-Metallic Co2tisi, Y. Jin, J. Waybright, P. Kharel, I. Tutic, J. Herran, P. Lukashev, S. Valloppilly, D. J. Sellmyer
Nebraska Center for Materials and Nanoscience: Faculty Publications
The structural, magnetic and electron-transport properties of Co2Ti1-xFexSi (x = 0, 0.25, 0.5) ribbons prepared by arc-melting and melt-spinning were investi- gated. The rapidly quenched Co2Ti0.5Fe0.5Si crystallized in the cubic L21 structure whereas Co2Ti0.75Fe0.25Si and Co2TiFe0Si showed various degrees of B2-type disorder. At room temperature, all the samples are ferromagnetic, and the Curie tem- perature increased from 360 K for Co2TiSi to about 800 K for Co2Ti0.5Fe0.5Si. The measured …
Laser-Assisted Nanowelding Of Graphene To Metals: An Optical Approach Toward Ultralow
Contact Resistance,
2017
University of Nebraska-Lincoln
Laser-Assisted Nanowelding Of Graphene To Metals: An Optical Approach Toward Ultralow Contact Resistance, K. Keramatnejad, Yunshen Zhou, Da Wei Li, Hossein Rabiee Golgir, Xi Huang, Qi Ming Zhou, Jingfeng Song, Stephen Ducharme, Yongfeng Lu
Stephen Ducharme Publications
The electrical performance of graphene-based devices is largely limited by substantial contact resistance at the heterodimensional graphene-metal junctions. A laserassisted nanowelding technique was developed to reduce graphene-metal (G-M) contact resistance and improve carrier injection in suspended graphene devices. Selective breakdown of C-C bonds and formation of structural defects were realized through laser irradiation at the edges of graphene within the G-M contact regions in order to increase the chemical reactivity of graphene, facilitate G-M bonding and, therefore, maximize interfacial carrier transportation. Through this method, significantly reduced G-M contact resistances, as low as 2.57 Ω-μm were obtained. In addition, it was …
Satellite Survivability In Space: A Materials Perspective,
2017
Utah State Univesity
Satellite Survivability In Space: A Materials Perspective, Jr Dennison
Presentations
No abstract provided.
Electron Yield Measurements Of High-Yield, Low-Conductivity Dielectric Materials,
2017
Utah State University
Electron Yield Measurements Of High-Yield, Low-Conductivity Dielectric Materials, Justin Christensen
Senior Theses and Projects
No abstract provided.
Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek,
2017
Utah State University
Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek, Tyler Kippen, Allen Andersen, Jr Dennison
Posters
No abstract provided.
Temporal And Spatial Correlations In Electron-Induced Arcs Of Adjacent Dielectric Islands,
2017
Utah State University
Temporal And Spatial Correlations In Electron-Induced Arcs Of Adjacent Dielectric Islands, Justin Christensen, Jr Dennison, Justin Dekany
Journal Articles
This study investigates very short duration (
Density Of State Models And Temperature Dependence Of Radiation Induced Conductivity,
2017
Utah State University
Density Of State Models And Temperature Dependence Of Radiation Induced Conductivity, Jodie Corbridge Gillespie, Jr Dennison, Alec M. Sim
Journal Articles
Expressions are developed for radiation induce conductivity (RIC) over an extended temperature range, based on density of states models for highly disordered insulating materials. A general discussion of the DOS of can be given using two simple types of DOS distributions of defect states within the bandgap for disordered materials are considered, one that monotonically decreases within the bandgap and one with a distribution peak within the band gap. Three monotonically decreasing models (exponential, power law, and linear), and two peaked models (Gaussian and delta function) are considered, plus limiting cases with a uniform DOS for each type. Variations using …
Theoretical Approach To Electroresistance In Ferroelectric Tunnel Junctions,
2017
Georgia Institute of Technology
Theoretical Approach To Electroresistance In Ferroelectric Tunnel Junctions, Sou-Chi Chang, Azad Naeemi, Dmitri E. Nikonov, Alexei Gruverman
Alexei Gruverman Publications
In this paper, a theoretical approach comprising the nonequilibrium Green’s function method for electronic transport and the Landau-Khalatnikov equation for electric polarization dynamics is presented to describe polarization-dependent tunneling electroresistance (TER) in ferroelectric tunnel junctions. Using appropriate contact, interface, and ferroelectric parameters, the measured current-voltage characteristic curves in both inorganic (Co/BaTiO3/La0.67Sr0.33MnO3) and organic (Au/PVDF/W) ferroelectric tunnel junctions can be well described by the proposed approach. Furthermore, under this theoretical framework, the controversy of opposite TER signs observed experimentally by different groups in Co/BaTiO3/La0.67Sr0.33MnO3 systems is …
Measuring And Modeling The Conductivity Of Highly Insulating Materials,
2017
Utah State University
Measuring And Modeling The Conductivity Of Highly Insulating Materials, David King
Senior Theses and Projects
No abstract provided.
Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings,
2017
Instituto de Ciencia de Materiales de Madrid
Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, Maria E. Davila, Jr Dennison
Presentations
No abstract provided.
