Now showing items 1-20 of 128

    • Mechanism of the anomalous temperature dependence of coercivity in Sm(Co, Fe, Cu, Zr)z high temperature magnets 

      Rong, Chuan-bing; Shen, Bao-gen; Zhang, Hong-wei; Liu, J. Ping (AIP, 2006)
      Coercivity mechanism of the precipitation-hardened Sm Co,Fe,Cu,Zr z high-temperature magnets was found to vary with temperature by measurements of reversible magnetization. The magnetization reversal is mainly controlled ...
    • Hard magnetic FePt nanoparticles by salt-matrix annealing 

      Nandwana, Vikas; Li, Daren; Poudyal, Narayan; Jin, Zhiqiang; Elkins, Kevin; Liu, J Ping (AIP, 2006)
      To transfer face-centered-cubic (fcc) FePt nanoparticles to the face-centered-tetragonal (fct) phase with high magnetic anisotropy, heat treatments are necessary. The heat treatments lead to agglomeration and sintering of ...
    • Mechanism of the anomalous temperature dependence of coercivity in Sm(Co,Fe,Cu,Zr)[subscript]z high-temperature magnets 

      Rong, Chuanbing; Zhang, Hong-wei; Shen, Bao-gen; Liu, J. Ping (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2006-01-24)
      Coercivity mechanism of the precipitation-hardened Sm(Co,Fe,Cu,Zr)z high-temperature magnets was found to vary with temperature by measurements of reversible magnetization. The magnetization reversal is mainly controlled ...
    • Hard magnetic FePt nanoparticles by salt-matrix annealing 

      Li, Daren; Poudyal, Narayan; Nandwana, Vikas; Jin, Zhiqiang; Elkins, Kevin; Liu, J. Ping (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2006-04-26)
      To transfer face-centered-cubic (fcc) FePt nanoparticles to the face-centered-tetragonal (fct) phase with high magnetic anisotropy, heat treatments are necessary. The heat treatments lead to agglomeration and sintering of ...
    • Transformation of electrical transport from variable range hopping to hard gap resistance in Zn[subscript]1−[subscript]xFe[subscript]xO[subscript]1[subscript]v magnetic semiconductor films 

      Tian, Y.F.; Yan, Shi-shen; Zhang, Y.P.; Song, H.Q.; Ji, G.; Liu, G.L.; Mei, M.L.; Liu, J. Ping; Altuncevahir, B.; Chakka, V.; Chen, Y.X. (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2006-11-16)
      Transformation of the electrical transport from the Efros and Shklovskii [J. Phys. C 8, L49 (1975)] variable range hopping to the “hard gap” resistance was experimentally observed in a low temperature range as the Fe ...
    • Bulk FePt/Fe3Pt nanocomposite magnets prepared by spark plasma sintering 

      Nandwana, Vikas; Rong, Chuan-Bing; Poudyal, Narayan; Liu, J. Ping; Saito, Tetsuji; Wu, Yaqiao; Kramer, Matthew J. (AIP, 2007)
      FePt/Fe3Pt bulk nanocomposite magnets have been prepared by the spark plasma sintering of chemically synthesized FePt and Fe3O4 nanoparticles under 100 MPa at 400–600 °C. It was found that the phase transition of the FePt ...
    • Bulk FePt-based nanocomposite magnets with enhanced exchange coupling 

      Nandwana, Vikas; Liu, J. Ping; Poudyal, Narayan; Rong, Chuan-Bing; Kozlov, Mikhail E.; Baughman, Ray H.; Ding, Yong; Wang, Zhong Lin (AIP, 2007)
      High density bulk FePt/Fe3Pt nanocomposite magnets have been prepared by high-pressure warm compaction of chemically synthesized FePt and Fe3O4 nanoparticles. It is found that the density increases with the compaction ...
    • Structural phase transition and ferromagnetism in monodisperse 3 nm FePt particles 

      Nandwana, Vikas; Rong, Chuan-bing; Chaubey, Girija S.; Skomski, R; Wu, Y.Q.; Kramer, M.J.; Liu, J. Ping (AIP, 2007)
      FePt nanoparticles with a size of 3 nm and thermally stable room-temperature ferromagnetism are investigated. The monodisperse nanoparticles were prepared by chemical synthesis and a salt-matrix annealing technique. ...
    • Curie temperatures of annealed FePt nanoparticle systems 

      Rong, Chuanbing; Li, Yang; Liu, J. Ping (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-03-28)
      The chemically synthesized FexPt100-x nanoparticles with controlled compositions were annealed to transfer the disordered face-centered-cubic structure to the ordered structure. It was found that the L10 FePt structure can ...
    • Bulk FePt/Fe3Pt nanocomposite magnets prepared by spark plasma sintering 

      Rong, Chuanbing; Nandwana, Vikas; Poudyal, Narayan; Liu, J. Ping; Saito, Tetsuji; Wu, Yaqiao; Kramer, Matthew J. (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-04-27)
      FePt/Fe3Pt bulk nanocomposite magnets have been prepared by the spark plasma sintering of chemically synthesized FePt and Fe3O4 nanoparticles under 100 MPa at 400–600 °C. It was found that the phase transition of the FePt ...
    • Temperature- and magnetic-field-induced phase transitions in Fe-rich FePt alloys 

      Rong, Chuanbing; Liu, J. Ping (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-06-01)
      Structural and magnetic properties of the FexPt100-x (x=78–88) alloys have been investigated. It is found that for all of the investigated compositions, a phase transition occurs from the disordered γ phase to the ordered ...
    • Bulk FePt-based nanocomposite magnets with enhanced exchange coupling 

      Rong, Chuanbing; Nandwana, Vikas; Poudyal, Narayan; Liu, J. Ping; Kozlov, Mikhail E.; Baughman, Ray H.; Ding, Yong; Wang, Zhong Lin (American Institute of PhysicsDepartment of Physics, The University of Texas at Arlington, 2007-07-23)
      High density bulk FePt/Fe3Pt nanocomposite magnets have been prepared by high-pressure warm compaction of chemically synthesized FePt and Fe3O4 nanoparticles. It is found that the density increases with the compaction ...
    • On The Behavior Of The 5f Electrons 

      Dholabhai, Pratik Pankajkumar (Physics, 2007-08-23)
      Considerable theoretical efforts have been devoted in recent years to studying the electronic and geometric structures and related properties of surfaces to high accuracy. One of the many motivations for this burgeoning ...
    • On A Class Of ABCS 

      Lalgudi Ganapathy, Sridevi (Physics, 2007-08-23)
      The local density approximation to density functional theory (LDA-DFT) has been used to study the different possible relaxations and reconstructions of In-rich InSb (100) surface. Various electronic and geometric structure ...
    • Effects Of Temperature Gradients On Transverse Oscillations Of Solar Magnetic Flux Tubes 

      Subramaniam, Shilpa (Physics, 2007-08-23)
      Solar magnetic flux tubes support three fundamental modes: longitudinal, transverse and torsional tube waves. Previous studies showed that the propagation of longitudinal and transverse waves along thin and isothermal ...
    • A First-principles Study On Bulk CuO: Electronic Structures And Native Point Defects 

      Wu, Dangxin (Physics, 2007-08-23)
      In this thesis, we have performed a first-principles study on strongly correlated monoclinic cupric oxide (CuO) by using the LSDA+U method implemented in the PAW method. Based on the optimized structural parameters, which ...
    • On The Existence And Stability Of Carbon -based Silicon Fullerenes -a Density Functional Theoretic Study 

      Srinivasan, Aravind (Physics, 2007-08-23)
      The electronic and geometric properties of silicon-carbon fullerene-like nanostructures with two, four, six, twenty and twenty four carbon atoms on the surface of the Si60 cages by substitution, as well as inside the cage ...
    • Holographic Patterning Of Polymer Dispersed Liquid Crystal Materials For Diffractive Optical Elements 

      Ramsey, Robert Allan (Physics, 2007-08-23)
      Liquid crystals are a soft condensed matter phase that share properties with both isotropic liquids and crystalline solids. Composite materials formed from both low molecular weight liquid crystals and polymers are of both ...
    • First Observation Of Dijet Events With An Antiproton Tag At [square root]s = 1.96 TEV Using The DØ Forward Proton Detector 

      Strang, Michael (Physics, 2007-08-23)
      The Forward Proton Detector (FPD) is a new sub-system of the DØ detector, a 5000 ton particle physics detector located at the Fermilab Tevatron proton-antiproton collider. The FPD was implemented for the Tevatron Run II ...
    • Case Studies Of The Circular Restricted Three Body Problem 

      Eberle, William Jason (Physics, 2007-08-23)
      In this thesis, the onset of instability for a planet which is part of a stellar binary system is investigated by running numerical simulations of the circular restricted three body problem. This study also makes use of a ...