Now showing items 6-25 of 58

    • Cell manipulation using magnetic nanowires 

      Hultgren, A.; Tanase, M.; Chen, C.S.; Meyer, G.J.; Reich, D.H. (American Institute of Physics, 2003-05-15)
      The use of magnetic nanowires is demonstrated as a method for the application of force to mammalian cells. Magnetic separations were carried out on populations of NIH-3T3 mouse fibroblast cells using ferromagnetic Ni wires ...
    • Central mode and spin confinement near the boundary of the superconducting phase in YBa2Cu3O6.353 (Tc=18 K) 

      Birgeneau, R.J.; Broholm, C.; Liang, R.; Yamani, Z.; Bonn, D.; Tun, Z.; Chung, J.-H.; Hardy, W.N.; Stock, C.; Buyers, W.J.L. (American Physical Society, 2006-03-01)
      We have mapped the neutron scattering spin spectrum at low energies in YBa2Cu3O6.353 (Tc=18 K), where the doping ~0.06 is near the critical value (pc=0.055) for superconductivity. No coexistence with long-range-ordered ...
    • Comparison of surface spin wave modes at Fe/MnF2 and Fe/Mn interfaces 

      Siu, I.L.; Islam, M.N.; Walker, J.C. (American Institute of Physics, 2000-11-01)
      We have studied the thermal demagnetization in semi-infinite ferromagnets in Fe/MnF2 and Fe/Mn bilayers using Mössbauer spectroscopy. We find that the hyperfine field at the Fe/MnF2 interface follows a quasilinear temperature ...
    • Comparison of the electron-spin-resonance linewidth in multilayered CuMn spin glasses with insulating versus conducting interlayers 

      Leslie-Pelecky, D.L.; VanWijland, F.; Hoff, C.N.; Cowen, J.A.; Gavrina, A.; Chien, C.-L. (American Institute of Physics, 1994-05-15)
      The temperature-dependent electron-spin-resonance linewidth ΔH(T) may be used to investigate the effect of the geometry and interlayer material on the magnetic properties of multilayered systems. We compare ΔH(T) in ...
    • Composite domain walls in flat nanomagnets: the magnetostatic limit 

      Youk, H.; Chern, G.-W.; Merit, K.; Oppenheimer, B.; Tchernyshyov, O. (American Institute of Physics, 2006-04-15)
      We discuss the structure of the so-called 'vortex' domain walls in soft magnetic nanoparticles. A wall of this kind is a composite object consisting of three elementary topological defects: two edge defects with winding ...
    • Condensation of magnons and spinons in a frustrated ladder 

      Fouet, J.-B.; Mila, F.; Clarke, D.; Youk, H.; Tchernyshyov, O.; Fendley, P.; Noack, R.M. (American Physical Society, 2006-06-01)
      Motivated by the ever-increasing experimental effort devoted to the properties of frustrated quantum magnets in a magnetic field, we present a careful and detailed theoretical analysis of a one-dimensional version of this ...
    • Coupled Magnetic and Ferroelectric Domains in Multiferroic Ni3V2O8 

      Chen, W.C.; Kenzelmann, M.; Gentile, T.R.; Chen, Y.; Cabrera, I.; Rogado, N.; Lawes, G.; Broholm, C.; Lynn, J.W.; Erwin, R.; Cava, R.J.; Leao, J.B. (American Physical Society, 2009-08-21)
      Electric control of multi-ferroic domains is demonstrated through polarized magnetic neutron diffraction. Cooling to the cycloidal multi-ferroic phase of Ni3V2O8 in an electric field E causes the incommensurate Bragg ...
    • Current and shot noise measurements in a carbon nanotube-based spin diode 

      Merchant, C.A.; Markovic, N. (American Institute of Physics, 2009-04-01)
      Low-temperature measurements of asymmetric carbon nanotube (CNT) quantum dots are reported. The CNTs are end-contacted with one ferromagnetic and one normal-metal electrode. The measurements show a spin-dependent rectification ...
    • Dependence of exchange coupling on antiferromagnetic layer thickness in NiFe/CoO bilayers 

      Ambrose, T.; Chien, C.-L. (American Institute of Physics, 1998-06-01)
      A systematic study of the dependence of exchange coupling in NiFe/CoO bilayers on CoO layer thickness tAF from 5 to 500 Å has been made. For large CoO thicknesses (tAF>100 Å), the exchange field varies as 1/tAF, whereas ...
    • Direct transition from a disordered to a multiferroic phase on a triangular lattice 

      Kenzelmann, M.; Lawes, G.; Harris, A.B.; Gasparovic, G.; Broholm, C.; Ramirez, A.P.; Jorge, G.A.; Jaime, M.; Park, S.; Huang, Q.; Shapiro, A.Y.; Demianets, L.A. (American Physical Society, 2007-06-29)
      We report the first direct transition from a paramagnetic and paraelectric phase to an incommensurate multiferroic in the triangular lattice antiferromagnet RbFe(MoO4)2. Ferroelectricity is observed only when the magnetic ...
    • Doubly exchange-biased NiCoO/NiFe/Cu/NiFe/NiCoO spin valves 

      Ambrose, T.; Liu, K.; Chien, C.-L. (American Institute of Physics, 1999-04-15)
      A new type of doubly exchange-biased Ni50Co50O/NiFe/Cu/NiFe/Ni30Co70O spin-valve structure, with two ferromagnetic layers exchange biased in opposite directions by two different antiferromagnetic layers is demonstrated. ...
    • Dynamics of a vortex domain wall in a magnetic nanostrip: application of the collective-coordinate approach 

      Clarke, D.J.; Tretiakov, O.A.; Chern, G.-W.; Bazaliy, Ya.B.; Tchernyshyov, O. (American Physical Society, 2008-10-01)
      The motion of a vortex domain wall in a ferromagnetic strip of submicron width under the influence of an external magnetic field exhibits three distinct dynamical regimes. In a viscous regime at low fields the wall moves ...
    • Dynamics of domain walls in magnetic nanostrips 

      Tretiakov, O.A.; Clarke, D.; Chern, G.-W.; Bazaliy, Ya.B.; Tchernyshyov, O. (American Physical Society, 2008-03-28)
      We express the dynamics of domain walls in ferromagnetic nanowires in terms of collective coordinates, generalizing Thiele[psila]s steady-state results. For weak external perturbations the dynamics is dominated by a few ...
    • Effect of spacer material on the magnetic surface anisotropy in ultrathin Fe70B30 multilayer films 

      Hicken, R.J.; Rado, G.T.; Chien, C.-L. (American Institute of Physics, 1991-04-15)
      It has been found recently that the magnetic surface anisotropy Ks in Fe70B30/Ag multilayer films decreases monotonically with magnetic layer thickness (2L) for 2L<16.5 Å. In order to determine possible effects of the ...
    • Effects of carrier mobility and morphology in organic semiconductor spin valves 

      Liu, Yaohua; Lee, Taegweo; Katz, Howard E.; Reich, Daniel H. (American Institute of Physics, 2009-05-01)
      We studied spin transport in four organic semiconductors (OSCs) with different electronic properties. Magnetoresistance (MR) effects were observed up to room temperature in junctions based on an electron-carrying OSC, ...
    • Evidence for decay of spin waves above the pseudogap of underdoped YBa2Cu3O6.35 

      Stock, C.; Cowley, R.A.; Buyers, W.J.L.; Coldea, R.; Broholm, C.; Frost, C.D.; Birgeneau, R.J.; Liang, R.; Bonn, D.; Hardy, W.N. (American Physical Society, 2007-05-01)
      The magnetic spectrum at high energies in heavily underdoped YBa2Cu3O6.35 (Tc=18 K) has been determined throughout the Brillouin zone. At low energy, the scattering forms a cone of spin excitations emanating from the ...
    • Exchange coupling between Cr and ferromagnetic thin films 

      Yang, F.Y.; Chien, C.-L. (American Institute of Physics, 2003-05-15)
      Exchange bias has been observed in Ni81Fe19/Cr bilayers. The exchange bias field for Cr thickness tCr larger than 62 Å increases with tCr and levels off at tCr=150 Å, whereas coercivity increases without saturation. The ...
    • Exploiting finite size effects in a novel core/shell microstructure 

      Liu, Zhu; Xia, Guoqiang; Zhu, Frank; Kim, Su; Markovic, Nina; Chien, Chia-Ling; Searson, Peter C. (American Institute of Physics, 2008-03-15)
      Electrodeposition of Ni-Cu alloys at high Cu(II) concentration and large overpotentials results in phase separation with a unique microstructure characterized by features with a copper-rich core and a nickel-rich shell. ...
    • Fermionic spin excitations in two- and three-dimensional antiferromagnets 

      Zhihao, Hao; Tchernyshyov, O. (American Physical Society, 2009-10-30)
      Spin excitations in an ordered Heisenberg magnet are magnons-bosons with spin 1. That may change when frustration and quantum fluctuations suppress the order and restore the spin-rotation symmetry. We show that spin ...
    • Field dependence of magnetic ordering in Kagome-staircase compound Ni3V2O8 

      Kenzelmann, M.; Harris, A.B.; Aharony, A.; Entin-Wohlman, O.; Yildirim, T.; Huang, Q.; Park, S.; Lawes, G.; Broholm, C.; Rogado, N.; Cava, R.J.; Kim, K.H.; Jorge, G.; Ramirez, A.P. (American Physical Society, 2006-07-01)
      We present powder and single-crystal neutron diffraction and bulk measurements of the Kagome-staircase compound Ni3V2O8 (NVO) in fields up to 8.5 T applied along the c direction. (The Kagome plane is the a-c plane.) This ...