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Magnetism

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Full-Text Articles in Physical Sciences and Mathematics

Electromagnetic Theory And Applications, Nicholas Madamopoulos, George Kliros Jan 2023

Electromagnetic Theory And Applications, Nicholas Madamopoulos, George Kliros

Open Educational Resources

This book intends to provide both the fundamentals of Electromagnetics but also some practical applications of the concepts covered. Having taught electromagnetics for several years, the authors feel that many times the field of electromagnetics comes as “old” and often times students do not appreciate the concepts and their importance in everyday applications. The authors intend to accompany the EM concepts with life applications. Hence, students may see the direct impact of the knowledge they acquire through the study of the field of electromagnetics and better appreciate the field.

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Pressure - Temperature Phase Diagram Of Crsite3, J L. Musfeldt, David Mandrus, Zhenxian Liu Jan 2023

Pressure - Temperature Phase Diagram Of Crsite3, J L. Musfeldt, David Mandrus, Zhenxian Liu

Chemistry Publications and Other Works

van der Waals solids are well known to host remarkable phase diagrams with competing phases, unusual energy transfer processes, and elusive states of matter. Among this class of materials, chalcogenides have emerged as the most flexible and relevant platforms for unraveling charge-structure-function relationships. In order to explore the properties of complex chalcogenides under external stimuli, we measured the far infrared spectroscopic response of CrSiTe3 under extreme pressure-temperature conditions. Analysis of the 368 cm−1 Si-Te stretching mode and the manner in which it is screened by the closure of the indirect gap reveals that the insulator-metal transition takes place immediately after …

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Magnetism Of Novel Rare-Earth-Free Intermetallic Compounds, Haohan Wang Jun 2022

Magnetism Of Novel Rare-Earth-Free Intermetallic Compounds, Haohan Wang

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Rare-earth-free magnets have drawn lots of interest because of their low cost, and the production is not limited by the shortage of rare-earth elements. This dissertation focuses on three rare-earth-free materials, Fe-Co-Ti alloys, Fe-Ni-B alloys, and Co-Si. All of them are synthesized by arc melting followed by melt-spinning. Fe3+xCo3−xTi2 (x = 0, 2, 3) alloys exhibit hexagonal crystal structures and show non-collinear spin structures according to neutron diffraction. The magnetic moments have projections on both the c-axis and basal plane, and the corresponding misalignment angle exhibits a nonlinear decrease with …

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Magnetism In Curved Geometries, R. Streubel, E. Y. Tsymbal, P. Fischer Jan 2021

Magnetism In Curved Geometries, R. Streubel, E. Y. Tsymbal, P. Fischer

Evgeny Tsymbal Publications

No abstract provided.

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Unconventional Josephson Junctions With Topological Kondo Insulator Weak Links, Xuecheng Ye, Jacob Cook, Erik D. Huemiller, Aaron D. K. Finck, P. K. Ghaemi, Thomas Vojta, For Full List Of Authors, See Publisher's Website. Sep 2019

Unconventional Josephson Junctions With Topological Kondo Insulator Weak Links, Xuecheng Ye, Jacob Cook, Erik D. Huemiller, Aaron D. K. Finck, P. K. Ghaemi, Thomas Vojta, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Proximity-induced superconductivity in three-dimensional (3D) topological insulators forms a new quantum phase of matter and accommodates exotic quasiparticles such as Majorana bound states. One of the biggest drawbacks of the commonly studied 3D topological insulators is the presence of conducting bulk that obscures both surface states and low energy bound states. Introducing superconductivity in topological Kondo insulators such as SmB6, however, is promising due to their true insulating bulk at low temperatures. In this work, we develop an unconventional Josephson junction by coupling superconducting Nb leads to the surface states of a SmB6 crystal. We observe a robust critical current …

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Tuning The Magnetic Ground State Of Ce1−Xybxrhin5 By Yb Valence Fluctuations, S. Jang, N. Pouse, T. Keiber, Benjamin White, S. M. Dissler, J. W. Lynn, J. C. Collini, M. Janoschek, F. Bridges, M. Brian Maple Nov 2018

Tuning The Magnetic Ground State Of Ce1−Xybxrhin5 By Yb Valence Fluctuations, S. Jang, N. Pouse, T. Keiber, Benjamin White, S. M. Dissler, J. W. Lynn, J. C. Collini, M. Janoschek, F. Bridges, M. Brian Maple

All Faculty Scholarship for the College of the Sciences

We characterize the properties of Ce1−xYbxRhIn5 single crystals with 0 ⩽ x ⩽ 1 using measurements of powder x-ray diffraction, energy dispersive x-ray spectroscopy, electrical resistivity, magnetic susceptibility, specific heat, x-ray absorption near edge structure (XANES), and neutron diffraction. The Yb valence vYb, calculated from the magnetic susceptibility and measured using XANES, decreases from 3+ at x = 0 to ∼2.1+ at xact = 0.2, where xact is the measured Yb concentration. A transition from incommensurate to commensurate antiferromagnetism is observed in neutron diffraction measurements …

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Observation Of A Pressure-Induced Transition From Interlayer Ferromagnetism To Intralayer Antiferromagnetism In Sr4Ru3O10, H. Zheng, W. H. Song, J. Terzic, H. D. Zhao, Y. F. Ni, Lance E. Delong, P. Schlottmann, G. Cao Aug 2018

Observation Of A Pressure-Induced Transition From Interlayer Ferromagnetism To Intralayer Antiferromagnetism In Sr4Ru3O10, H. Zheng, W. H. Song, J. Terzic, H. D. Zhao, Y. F. Ni, Lance E. Delong, P. Schlottmann, G. Cao

Physics and Astronomy Faculty Publications

Sr4Ru3O10 is a Ruddlesden-Popper compound with triple Ru-O perovskite layers separated by Sr-O rock-salt layers. This compound presents a rare coexistence of interlayer (c-axis) ferromagnetism and intralayer (basal-plane) metamagnetism at ambient pressure. Here we report the observation of pressure-induced, intralayer itinerant antiferromagnetism arising from the interlayer ferromagnetism. The application of modest hydrostatic pressure generates an anisotropy that may cause a flattening and a tilting of RuO6 octahedra. All magnetic and transport results from this study indicate these lattice distortions diminish the c-axis ferromagnetism and basal-plane metamagnetism, and induce a basal-plane antiferromagnetic state. …

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Ambipolar Ferromagnetism By Electrostatic Doping Of A Manganite, L. M. Zheng, X. Renshaw Wang, W. M. Lü, C. J. Li, Tula R. Paudel, Z. Q. Liu, Z. Huang, S. W. Zeng, Kun Han, Z. H. Chen, X. P. Qiu, M. S. Li, Shize Yang, B. Yang, Matthew F. Chisholm, L. W. Martin, S. J. Pennycook, Evgeny Y. Tsymbal, J. M. D. Coey, W. W. Cao May 2018

Ambipolar Ferromagnetism By Electrostatic Doping Of A Manganite, L. M. Zheng, X. Renshaw Wang, W. M. Lü, C. J. Li, Tula R. Paudel, Z. Q. Liu, Z. Huang, S. W. Zeng, Kun Han, Z. H. Chen, X. P. Qiu, M. S. Li, Shize Yang, B. Yang, Matthew F. Chisholm, L. W. Martin, S. J. Pennycook, Evgeny Y. Tsymbal, J. M. D. Coey, W. W. Cao

Evgeny Tsymbal Publications

Complex-oxide materials exhibit physical properties that involve the interplay of charge and spin degrees of freedom. However, an ambipolar oxide that is able to exhibit both electron-doped and hole-doped ferromagnetism in the same material has proved elusive. Here we report ambipolar ferromagnetism in LaMnO3, with electron–hole asymmetry of the ferromagnetic order. Starting from an undoped atomically thin LaMnO3 film, we electrostatically dope the material with electrons or holes according to the polarity of a voltage applied across an ionic liquid gate. Magnetotransport characterization reveals that an increase of either electron-doping or hole-doping induced ferromagnetic order in this …

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Proximitized Materials, Igor Žutić, Alex Matos-Abiague, Benedikt Scharf, Hanan Dery, Kirill Belashchenko May 2018

Proximitized Materials, Igor Žutić, Alex Matos-Abiague, Benedikt Scharf, Hanan Dery, Kirill Belashchenko

Department of Physics and Astronomy: Faculty Publications

Advances in scaling down heterostructures and having an improved interface quality together with atomically thin two-dimensional materials suggest a novel approach to systematically design materials. A given material can be transformed through proximity effects whereby it acquires properties of its neighbors, for example, becoming superconducting, magnetic, topologically nontrivial, or with an enhanced spin-orbit coupling. Such proximity effects not only complement the conventional methods of designing materials by doping or functionalization but can also overcome their various limitations. In proximitized materials it is possible to realize properties that are not present in any constituent region of the considered heterostructure. While the …

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Efficacy Of Multimedia Learning Modules As Preparation For Lecture-Based Tutorials In Electromagnetism, James Christopher Moore Feb 2018

Efficacy Of Multimedia Learning Modules As Preparation For Lecture-Based Tutorials In Electromagnetism, James Christopher Moore

Physics Faculty Publications

We have investigated the efficacy of on-line, multimedia learning modules (MLMs) as preparation for in-class, lecture-based tutorials in electromagnetism in a physics course for natural science majors (biology and marine science). Specifically, we report the results of a multiple-group pre/post-test research design comparing two groups receiving different treatments with respect to activities preceding participation in Tutorials in Introductory Physics. The different pre-tutorial activities were as follows: (1) students were assigned reading from a traditional textbook, followed by a traditional lecture; and (2) students completed on-line MLMs developed by the Physics Education Research Group at the University of Illinois at Urbana …

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Magnetic Domain Morphology In [Co(4a)/Pt(7a] Thin Film, Jeremy Metzner Aug 2017

Magnetic Domain Morphology In [Co(4a)/Pt(7a] Thin Film, Jeremy Metzner

Student Works

A collection of results for multi-layered thin films and their magnetic domains.

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Suppression Of Magnetism In Ba5Alir2O11: Interplay Of Hund's Coupling, Molecular Orbitals, And Spin-Orbit Interaction, Sergey V. Streltsov, Gang Cao, Daniel I. Khomskii Jul 2017

Suppression Of Magnetism In Ba5Alir2O11: Interplay Of Hund's Coupling, Molecular Orbitals, And Spin-Orbit Interaction, Sergey V. Streltsov, Gang Cao, Daniel I. Khomskii

Center for Advanced Materials Faculty Publications

The electronic and magnetic properties of Ba5AlIr2O11 containing Ir-Ir dimers are investigated using the generalized gradient approximation (GGA) and GGA + spin-orbit coupling (SOC) calculations. We found that the strong suppression of the magnetic moment in this compound recently found by Terzic et al. [Phys. Rev. B 91, 235147 (2015)] is not due to charge ordering but is related to the joint effect of the spin-orbit interaction and strong covalency, resulting in the formation of metal-metal bonds. They conspire and act against the intraatomic Hund's rule exchange interaction to reduce total magnetic moment of the …

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Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das Apr 2017

Fabrication And Study Of The Structure And Magnetism Of Rare-Earth Free Nanoclusters, Bhaskar Das

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

No abstract provided.

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Gapless Symmetry-Protected Topological Order, Thomas Scaffidi, Daniel E. Parker, Romain Vasseur Jan 2017

Gapless Symmetry-Protected Topological Order, Thomas Scaffidi, Daniel E. Parker, Romain Vasseur

Physics Department Faculty Publication Series

We introduce exactly solvable gapless quantum systems in d dimensions that support symmetry-protected topological (SPT) edge modes. Our construction leads to long-range entangled, critical points or phases that can be interpreted as critical condensates of domain walls “decorated” with dimension (d−1) SPT systems. Using a combination of field theory and exact lattice results, we argue that such gapless SPT systems have symmetry-protected topological edge modes that can be either gapless or symmetry broken, leading to unusual surface critical properties. Despite the absence of a bulk gap, these edge modes are robust against arbitrary symmetry-preserving local perturbations near the …

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Defect Driven Magnetism In Doped Sno2 Nanoparticles: Surface Effects, Pushpa Raghani, Pankaj Kumar, Balaji Ramanujam, Alex Punnoose Jun 2016

Defect Driven Magnetism In Doped Sno2 Nanoparticles: Surface Effects, Pushpa Raghani, Pankaj Kumar, Balaji Ramanujam, Alex Punnoose

Physics Faculty Publications and Presentations

Magnetism and energetics of intrinsic and extrinsic defects and defect clusters in bulk and surfaces of SnO2 is investigated using first-principles to understand the role of surfaces in inducing magnetism in Zn doped nanoparticles. We find that Sn vacancies induce the largest magnetic moment in bulk and on surfaces. However, they have very large formation energies in bulk as well as on surfaces. Oxygen vacancies on the other hand are much easier to create than VSn, but neutral and VO+2 vacancies do not induce any magnetism in bulk as well as on surfaces. VO …

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Ground-State Tuning Of Metal-Insulator Transition By Compositional Variations In Bair1−XRuXO3 (0 ≤ X ≤ 1), Shujuan Yuan, Kamal H. Butrouna, Jsaminka Terzic, Hao Zheng, Saicharan Aswartham, Lance E. Delong, Feng Ye, P. Schlottmann, Gang Cao Apr 2016

Ground-State Tuning Of Metal-Insulator Transition By Compositional Variations In Bair1−XRuXO3 (0 ≤ X ≤ 1), Shujuan Yuan, Kamal H. Butrouna, Jsaminka Terzic, Hao Zheng, Saicharan Aswartham, Lance E. Delong, Feng Ye, P. Schlottmann, Gang Cao

Physics and Astronomy Faculty Publications

Hexagonal BaIrO3 is a magnetic insulator driven by the spin-orbit interaction (SOI), whereas BaRuO3 is an enhanced paramagnetic metal. Our investigation of structural, magnetic, transport, and thermal properties reveals that substitution of Ru4+ (4d4) ions for Ir4+ (5d5) ions in BaIrO3 reduces the magnitudes of the SOI and a monoclinic structural distortion and rebalances the competition between the SOI and the lattice degrees of freedom to render an evolution from a magnetic insulting state to a robust metallic state. The central findings of this paper are as follows: (1) light …

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Interface‐Coupled Bifeo3/Bimno3 Superlattices With Magnetic Transition Temperature Up To 410 K, Eun-Mi Choi, Josée E. Kliebeuker, Thomas Fix, Jie Xiong, Christy J. Kinane, Dario Arena, Sean Langridge, Aiping Chen, Zhenxing Bi, Joon Hwan Lee, Quanix Jia, Mark G. Blamire, Judith L. Macmanus-Driscoll Mar 2016

Interface‐Coupled Bifeo3/Bimno3 Superlattices With Magnetic Transition Temperature Up To 410 K, Eun-Mi Choi, Josée E. Kliebeuker, Thomas Fix, Jie Xiong, Christy J. Kinane, Dario Arena, Sean Langridge, Aiping Chen, Zhenxing Bi, Joon Hwan Lee, Quanix Jia, Mark G. Blamire, Judith L. Macmanus-Driscoll

Physics Faculty Publications

Enhanced magnetic transition temperatures are demonstrated in 50 nm thick (001)‐oriented (BiFeO3)m/(BiMnO3)m (BFO/BMO) superlattices (SL). Highly strained ultra‐short SLs showed a magnetic transition, TC2, up to ≈410 K as a result of ferrimagnetic interaction between BFO/BMO. All SL showed a new ferromagnetic transtion, TC1, of ≈150 K coming from Fe4+‐Fe4+ interaction explained by electron transfer/leakage from Fe3+ to Mn3+.

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Electron Heat Flow Due To Magnetic Field Fluctuations, Jeong-Young Ji, Gunyoung Park, Sung Sik Kim, Eric D. Held Jan 2016

Electron Heat Flow Due To Magnetic Field Fluctuations, Jeong-Young Ji, Gunyoung Park, Sung Sik Kim, Eric D. Held

All Physics Faculty Publications

Radial heat transport induced by magnetic field line fluctuations is obtained from the integral parallel heat flow closure for arbitrary collisionality. The parallel heat flow and its radial component are computed for a single harmonic sinusoidal field line perturbation. In the collisional and collisionless limits, averaging the heat flow over an unperturbed surface yields Rechester-Rosenbluth like formulae with quantitative factors. The single harmonic result is generalized to multiple harmonics given a spectrum of small magnetic perturbations. In the collisionless limit, the heat and particle transport relations are also derived. © 2016 IOP Publishing Ltd.

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Evolution Of Magnetism In Single-Crystal Ca2Ru1−XIrXO4(0≤X≤0.65), Shujuan Yuan, Jsaminka Terzic, J. C. Wang, L. Li, Saicharan Aswartham, W. H. Song, F. Ye, Gang Cao Jul 2015

Evolution Of Magnetism In Single-Crystal Ca2Ru1−XIrXO4(0≤X≤0.65), Shujuan Yuan, Jsaminka Terzic, J. C. Wang, L. Li, Saicharan Aswartham, W. H. Song, F. Ye, Gang Cao

Physics and Astronomy Faculty Publications

We report structural, magnetic, transport, and thermal properties of single-crystal Ca2Ru1−xIrxO4(0≤x≤0.65). Ca2RuO4 is a structurally driven Mott insulator with a metal-insulator transition at TMI=357K, which is well separated from antiferromagnetic order at TN=110K. Substitution of a 5d element, Ir, for Ru enhances spin-orbit coupling and locking between the structural distortions and magnetic moment canting. Ir doping intensifies the distortion or rotation of Ru/IrO6 octahedra and induces weak ferromagnetic behavior along the c axis. In particular, Ir doping suppresses TN but …

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Magnetic Fields, Voltage, And Currents Problems (Practice Questions), Arun Saha Apr 2015

Magnetic Fields, Voltage, And Currents Problems (Practice Questions), Arun Saha

Physics and Astronomy Ancillary Materials

This set of lecture-oriented practice questions was developed under a Round One ALG Textbook Transformation Grant.

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Giant Magnetization Canting Due To Symmetry Breaking In Zigzag Co Chains On Ir(001), B. Dupé, Jessica E. Bickel, Y. Mokrousov, F. Otte, Kirsten Von Bergmann, André Kubetzka, Stefan Heinze, Roland Wiesendanger Feb 2015

Giant Magnetization Canting Due To Symmetry Breaking In Zigzag Co Chains On Ir(001), B. Dupé, Jessica E. Bickel, Y. Mokrousov, F. Otte, Kirsten Von Bergmann, André Kubetzka, Stefan Heinze, Roland Wiesendanger

Physics Faculty Publications

We demonstrate a canted magnetization of biatomic zigzag Co chains grown on the (5 × 1) reconstructed Ir(001) surface using density functional theory (DFT) calculations and spin-polarized scanning tunneling microscopy (SP-STM) experiments. It is observed by STM that biatomic Co chains grow in three different structural configurations. Our DFT calculations show that they are all in a ferromagnetic (FM) state. Two chain types possess high symmetry due to two equivalent atomic strands and an easy magnetization direction that is along one of the principal crystallographic axes. The easy magnetization axis of the zigzag Co chains is canted away from the …

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Particle Moment Canting In Cofe2o4 Nanoparticles, K. Hasz, Yumi Ijiri, Kathryn L. Krycka, Julie A. Borchers, R.A. Booth, S. Oberdick, S.A. Majetich Nov 2014

Particle Moment Canting In Cofe2o4 Nanoparticles, K. Hasz, Yumi Ijiri, Kathryn L. Krycka, Julie A. Borchers, R.A. Booth, S. Oberdick, S.A. Majetich

Faculty & Staff Scholarship

Polarization-analyzed small-angle neutron scattering methods are used to determine the spin morphology in high crystalline anisotropy, 11 nm diameter CoFe2O4 nanoparticle assemblies with randomly oriented easy axes. In moderate to high magnetic fields, the nanoparticles adopt a uniformly canted structure, rather than forming domains, shells, or other arrangements. The observed canting angles agree quantitatively with those predicted from an energy model dominated by Zeeman and anisotropy competition, with implications for the technological use of such nanoparticles.

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Lattice-Tuned Magnetism Of Ru4+(4D4) Ions In Single Crystals Of The Layered Honeycomb Ruthenates Li2Ruo3 And Na2Ruo3, J. C. Wang, Jsaminka Terzic, T. F. Qi, Feng Ye, Shujuan Yuan, Saicharan Aswartham, S. V. Streltsov, D. I. Khomskii, Ribku K. Kaul, Gang Cao Oct 2014

Lattice-Tuned Magnetism Of Ru4+(4D4) Ions In Single Crystals Of The Layered Honeycomb Ruthenates Li2Ruo3 And Na2Ruo3, J. C. Wang, Jsaminka Terzic, T. F. Qi, Feng Ye, Shujuan Yuan, Saicharan Aswartham, S. V. Streltsov, D. I. Khomskii, Ribku K. Kaul, Gang Cao

Physics and Astronomy Faculty Publications

We synthesize and study single crystals of the layered honeycomb lattice Mott insulators Na2RuO3 and Li2RuO3 with magnetic Ru4+(4d4) ions. The newly found Na2RuO3 features a nearly ideal honeycomb lattice and orders antiferromagnetically at 30 K. Single crystals of Li2RuO3 adopt a honeycomb lattice with either C2/m or more distorted P21/m below 300 K, depending on detailed synthesis conditions. We find that Li2RuO3 in both structures hosts a well-defined magnetic state, in contrast to …

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Boron Nitride Nanotubes For Spintronics, Kamal B. Dhungana, Ranjit Pati Sep 2014

Boron Nitride Nanotubes For Spintronics, Kamal B. Dhungana, Ranjit Pati

Department of Physics Publications

With the end of Moore's law in sight, researchers are in search of an alternative approach to manipulate information. Spintronics or spin-based electronics, which uses the spin state of electrons to store, process and communicate information, offers exciting opportunities to sustain the current growth in the information industry. For example, the discovery of the giant magneto resistance (GMR) effect, which provides the foundation behind modern high density data storage devices, is an important success story of spintronics; GMR-based sensors have wide applications, ranging from automotive industry to biology. In recent years, with the tremendous progress in nanotechnology, spintronics has crossed …

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Evidence For Magnetic Clusters In Ni₁₋ₓvₓ Close To The Quantum Critical Concentration, R. Wang, S. Ubaid-Kassis, A. Schroeder, P. J. Baker, F. L. Pratt, S. J. Blundell, T. Lancaster, I. Franke, J. S. Möller, Thomas Vojta Jul 2014

Evidence For Magnetic Clusters In Ni₁₋ₓvₓ Close To The Quantum Critical Concentration, R. Wang, S. Ubaid-Kassis, A. Schroeder, P. J. Baker, F. L. Pratt, S. J. Blundell, T. Lancaster, I. Franke, J. S. Möller, Thomas Vojta

Physics Faculty Research & Creative Works

The d-metal alloy Ni1-xVx undergoes a quantum phase transition from a ferromagnetic ground state to a paramagnetic ground state as the vanadium concentration x is increased. We present magnetization, ac-susceptibility and muon-spin relaxation data at several vanadium concentrations near the critical concentration xc ~ 11.6 % at which the onset of ferromagnetic order is suppressed to zero temperature. Below xc, the muon data reveal a broad magnetic field distribution indicative of a long-range ordered ferromagnetic state with spatial disorder. We show evidence of magnetic clusters in the ferromagnetic phase and close to the phase …

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Novel Magnetism Of Ir5+(5D4) Ions In The Double Perovskite Sr2Yiro6, Gang Cao, Tongfei Qi, Li Li, Jsaminka Terzic, Shujuan Yuan, Lance E. De Long, Ganpathy Murthy, Ribhu K. Kaul Feb 2014

Novel Magnetism Of Ir5+(5D4) Ions In The Double Perovskite Sr2Yiro6, Gang Cao, Tongfei Qi, Li Li, Jsaminka Terzic, Shujuan Yuan, Lance E. De Long, Ganpathy Murthy, Ribhu K. Kaul

Physics and Astronomy Faculty Publications

We synthesize and study single crystals of a new double-perovskite Sr2YIrO6. Despite two strongly unfavorable conditions for magnetic order, namely, pentavalent Ir5+(5d4) ions which are anticipated to have Jeff=0 singlet ground states in the strong spin-orbit coupling (SOC) limit and geometric frustration in a face-centered cubic structure formed by the Ir5+ ions, we observe this iridate to undergo a novel magnetic transition at temperatures below 1.3 K. We provide compelling experimental and theoretical evidence that the origin of magnetism is in an unusual interplay between strong noncubic crystal …

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Evolution Of Magnetism In The Single-Crystal Honeycomb Iridates (Na1−XLiX)2Iro3, Gang Cao, Tongfei Qi, L. Li, Jsaminka Terzic, Vincent Shian Cao, Shujuan Yuan, M. Tovar, Ganpathy Murthy, Ribhu K. Kaul Dec 2013

Evolution Of Magnetism In The Single-Crystal Honeycomb Iridates (Na1−XLiX)2Iro3, Gang Cao, Tongfei Qi, L. Li, Jsaminka Terzic, Vincent Shian Cao, Shujuan Yuan, M. Tovar, Ganpathy Murthy, Ribhu K. Kaul

Physics and Astronomy Faculty Publications

We report the successful synthesis of single crystals of the layered iridate (Na1−xLix)2IrO3, 0 ≤ x ≤ 0.9, and a thorough study of its structural, magnetic, thermal, and transport properties. This compound allows a controlled interpolation between Na2IrO3 and Li2IrO3, while maintaining the quantum magnetism of the honeycomb Ir4+ planes. The measured phase diagram demonstrates a suppression of the Néel temperature TN at an intermediate x, indicating that the magnetic orders in Na2IrO3 and Li2IrO3 …

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Magnetism Of Films, Yi Liu, David J. Sellmyer Jan 2013

Magnetism Of Films, Yi Liu, David J. Sellmyer

David Sellmyer Publications

Films of L10-structure Fe50–xCoxPt50 films are synthesized by co-sputtering Fe, Co, and Pt on (001) MgO substrates and Si substrates with in-situ heating at 830°C. The nanostructures and magnetic properties of the films are characterized by X-ray diffraction, transmission electron microscopy, and SQUID. The compositions of the samples Fe50–xCoxPt50 are designed to maintain an atomic (Fe+Co):Pt ratio of 50:50 while increasing the Co content in each successive sample. In all samples, the X-ray diffraction patterns from samples on MgO substrate exhibit three strong peaks, namely L10Fe50–xCoxPt50 (001), (002), and MgO (002). The X-ray and electron diffraction patterns from …

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The History Of Maxwell's Equations, Lindsay Guilmette (Class Of 2012) Jan 2012

The History Of Maxwell's Equations, Lindsay Guilmette (Class Of 2012)

Writing Across the Curriculum

An enormous amount of technology is owed to Maxwell's theory of electromagnetism and his perseverance through cultural obstacles to advocate his talent of mathematical interpretation.

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Thermodynamics Of Magnetic Multilayers, Tathagata Mukherjee Nov 2011

Thermodynamics Of Magnetic Multilayers, Tathagata Mukherjee

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Our interest in thermodynamics of magnetic thin film heterostructure began by exploring the possibility to use magnetic nanostructures in the search for optimized magnetocaloric materials for potential room temperature refrigeration. In the present thesis magnetic thin film heterostructures are experimentally realized by Molecular Beam Epitaxy (MBE) and Pulsed Laser Deposition (PLD). Co/Cr and Fe/Cr superlattices were fabricated using mean-field theoretical concepts as guiding principles. The potential of artificial antiferromagnets for near room-temperature refrigeration is explored. Magnetocaloric properties are deduced from measurements of the temperature and field dependence of the magnetization of our samples. The effects of intra-plane and inter-plane exchange …

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