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

Electromagnetics and Photonics Commons

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

Articles 1 - 11 of 11

Full-Text Articles in Electromagnetics and Photonics

Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen Jan 2021

Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen

Physics Faculty Publications

Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. They operate at liquid helium temperatures (2–4 K) to achieve very high quality factors (1010–1011). Trapping of magnetic flux within the superconductor is a significant contribution to the residual RF losses, which limit the achievable quality factor. Suitable diagnostic tools are in high demand to understand the mechanisms of flux trapping in technical superconductors, and the fundamental components of such diagnostic tools are magnetic field sensors. We have studied the performance of commercially available Hall probes, anisotropic magnetoresistive sensors, and flux-gate magnetometers with …


Technobiology Paradigm In Nanomedicine: Treating Cancer With Magnetoelectric Nanoparticles, Emmanuel Stimphil Nov 2017

Technobiology Paradigm In Nanomedicine: Treating Cancer With Magnetoelectric Nanoparticles, Emmanuel Stimphil

FIU Electronic Theses and Dissertations

Today, cancer is the world’s deadliest disease. Despite significant progress to find a cure, especially over the last decade, with immunotherapy rapidly becoming the state of the art, major open questions remain. Each successful therapy is not only limited to a few cancers but also has relatively low specificity to target cancer cells; although cancer cells can indeed be eradicated, many normal cells are sacrificed as collateral damage. To fill this gap, we have developed a class of multiferroic nanostructures known as magnetoelectric nanoparticles (MENs) that can be used to enable externally controlled high-specificity targeted delivery and release of therapeutic …


Neutral Nitrogen Acceptors In Zno: The 67Zn Hyperfine Interactions, Eric M. Golden, S. M. Evans, Larry E. Halliburton, Nancy C. Giles Mar 2014

Neutral Nitrogen Acceptors In Zno: The 67Zn Hyperfine Interactions, Eric M. Golden, S. M. Evans, Larry E. Halliburton, Nancy C. Giles

Faculty Publications

Electron paramagnetic resonance (EPR) is used to characterize the 67Zn hyperfine interactions associated with neutral nitrogen acceptors in zinc oxide. Data are obtained from an n-type bulk crystal grown by the seeded chemical vapor transport method. Singly ionized nitrogen acceptors (N) initially present in the crystal are converted to their paramagnetic neutral charge state (N0) during exposure at low temperature to 442 or 633 nm laser light. The EPR signals from these N0 acceptors are best observed near 5 K. Nitrogen substitutes for oxygen ions and has four nearest-neighbor cations. The zinc ion …


Flicker Noise In Yba₂Cu₃O₇₋Δ Bicrystal Grain-Boundary Junctions In Weak Magnetic-Fields, Charles Surya, N. E. Israeloff, A. Widom, R. Seed, C. Vittoria Jan 2014

Flicker Noise In Yba₂Cu₃O₇₋Δ Bicrystal Grain-Boundary Junctions In Weak Magnetic-Fields, Charles Surya, N. E. Israeloff, A. Widom, R. Seed, C. Vittoria

Nathan Israeloff

Flicker noise in c-axis oriented long YBCO bicrystal grain boundary junctions was characterized as a function of temperature, biasing conditions, and magnetic field applied perpendicular to the a-b plane over a wide range of temperatures from 15 K to over 70 K. Aperiodic variations, as a function of magnetic field, were observed in both the junction voltages, V-J, and the flicker noise magnitude under constant current bias as the magnetic field was scanned from 0 to 8 G. The noise magnitudes were found to peak at the minima of V-J. Analyses of the field dependencies of the: magnitudes and the …


Tunable Fringe Magnetic Fields Induced By Converse Magnetoelectric Coupling In A Fega/Pmn-Pt Multiferroic Heterostructure, Trifon Fitchorov, Yajie Chen, Bolin Hu, Scott M. Gillette, Anton Geiler, Carmine Vittoria, Vincent G. Harris Aug 2013

Tunable Fringe Magnetic Fields Induced By Converse Magnetoelectric Coupling In A Fega/Pmn-Pt Multiferroic Heterostructure, Trifon Fitchorov, Yajie Chen, Bolin Hu, Scott M. Gillette, Anton Geiler, Carmine Vittoria, Vincent G. Harris

Anton Geiler

The fringe magnetic field, induced by magnetoelectric coupling in a bilayer Fe-Ga/Pb(Mg1/3Nb2/3)O3_PbTiO3 (PMN-PT) multifunctional composite, was investigated. The induced external field is characterized as having a butterfly hysteresis loop when tuned by an applied electric field. A tuning coefficient of the electrically induced fringe magnetic field is derived from the piezoelectric and magnetostrictive properties of the composite. A measured maximum tuning coefficient, 4.5 Oe/(kV cm−1), is found to agree well with theoretical prediction. This work establishes a foundation in the design of transducers based on the magnetoelectric effect.


Domain Rotation Induced Strain Effect On The Magnetic And Magneto-Electric Response In Cofe2o₄/Pb(Mg,Nb)O₃-Pbtio₃ Heterostructures, Zhiguang Wang, Ravindranath Viswan, Bolin Hu, Jie-Fang Li, V. G. Harris, D. Viehland Aug 2013

Domain Rotation Induced Strain Effect On The Magnetic And Magneto-Electric Response In Cofe2o₄/Pb(Mg,Nb)O₃-Pbtio₃ Heterostructures, Zhiguang Wang, Ravindranath Viswan, Bolin Hu, Jie-Fang Li, V. G. Harris, D. Viehland

Vincent G. Harris

The present work shows good control of both magnetic and electric properties with electric and magnetic fields, respectively, for epitaxial CoFe2O4 (CFO) films on Pb(Mg,Nb)O3-PbTiO3 (PMN-PT). X-ray reciprocal space mapping revealed a transformation between a- and c-domains in the PMN-PT under electric field (E). Magnetic hysteresis loop and magnetic force microscopy (MFM) measurements showed a considerable change in the magnetic properties in specific areas of CFO layers poled by MFM probe tips. Furthermore, a pulsed electric field applied to the substrate was found to switch the magnetization of CFO between high and low values, depending on the polarity of E.


Tunable Fringe Magnetic Fields Induced By Converse Magnetoelectric Coupling In A Fega/Pmn-Pt Multiferroic Heterostructure, Trifon Fitchorov, Yajie Chen, Bolin Hu, Scott Gillette, Anton Geiler, Carmine Vittoria, Vincent Harris Aug 2013

Tunable Fringe Magnetic Fields Induced By Converse Magnetoelectric Coupling In A Fega/Pmn-Pt Multiferroic Heterostructure, Trifon Fitchorov, Yajie Chen, Bolin Hu, Scott Gillette, Anton Geiler, Carmine Vittoria, Vincent Harris

Vincent G. Harris

The fringe magnetic field, induced by magnetoelectric coupling in a bilayer Fe-Ga/Pb(Mg1/3Nb2/3)O3_PbTiO3 (PMN-PT) multifunctional composite, was investigated. The induced external field is characterized as having a butterfly hysteresis loop when tuned by an applied electric field. A tuning coefficient of the electrically induced fringe magnetic field is derived from the piezoelectric and magnetostrictive properties of the composite. A measured maximum tuning coefficient, 4.5 Oe/(kV cm−1), is found to agree well with theoretical prediction. This work establishes a foundation in the design of transducers based on the magnetoelectric effect.


Insertion Of Lithium Ions Into Tio2 (Rutile) Crystals: An Electron Paramagnetic Resonance Study Of The Li-Associated Ti3+ Small Polaron, A. T. Brant, Nancy C. Giles, Larry E. Halliburton Feb 2013

Insertion Of Lithium Ions Into Tio2 (Rutile) Crystals: An Electron Paramagnetic Resonance Study Of The Li-Associated Ti3+ Small Polaron, A. T. Brant, Nancy C. Giles, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify a Ti3+-Li+ complex in TiO2 crystals having the rutile structure. This defect consists of an interstitial Li+ ion adjacent to a substitutional Ti3+ ion (the unpaired electron on the Ti3+ ion provides charge compensation for the Li+ ion). The neutral Ti3+-Li+ complex is best described as a donor-bound small polaron and is similar in structure to the recently reported neutral fluorine and hydrogen donors in TiO2 (rutile). Lithium ions are diffused into the crystals at …


Application Of Chebyshev Formalism To Identify Nonlinear Magnetic Field Components In Beam Transport System, Michael Spata Jul 2012

Application Of Chebyshev Formalism To Identify Nonlinear Magnetic Field Components In Beam Transport System, Michael Spata

Physics Theses & Dissertations

An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a beam-based technique for characterizing the extent of the nonlinearity of the magnetic fields of a beam transport system. Horizontally and vertically oriented pairs of air-core kicker magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the beam orbit relative to the unperturbed reference orbit. Fourier decomposition of the position data at eight different points along the beamline was then used to measure the amplitude of these frequencies. For a purely linear transport system one expects to find solely the …


Field Induced Structural Phase Transition At Temperatures Above The Curie Point In Gd5(Sixge1−X)4, Ravi L. Hadimani, Y. Melikhov, J. E. Snyder, David C. Jiles Jan 2009

Field Induced Structural Phase Transition At Temperatures Above The Curie Point In Gd5(Sixge1−X)4, Ravi L. Hadimani, Y. Melikhov, J. E. Snyder, David C. Jiles

David C. Jiles

Gd5(SixGe1−x)4 exhibits a field induced first order phase transition from a monoclinic paramagnetic to an orthorhombic ferromagnetic at temperatures above its Curie temperature for 0.41≤x≤0.51. The field required to induce the transition increases with temperature. This field induced first order phase transition was observed even above the projected second order phase transitiontemperature of the orthorhombic phase. This may be due to the fact that the applied magnetic field is so high that it causes the broadening to a wider range of higher temperatures of the second order phase transition of the orthorhombic phase, and at such high magnetic fields the …


Effects On Electrolytic Cells Of Magnetic Fields Applied To Single Electrodes, Craig Allen Cousins Oct 1982

Effects On Electrolytic Cells Of Magnetic Fields Applied To Single Electrodes, Craig Allen Cousins

Dissertations and Theses

The primary goal of this research was to investigate the effects associated with the application of magnetic fields to single electrodes.