Browsing Condensed Matter Physics by Title

Now showing items 1-20 of 58

    • Anisotropic three-dimensional magnetism in CaFe2As2 

      McQueeney, R. J.; Diallo, S. O.; Antropov, V. P.; Samolyuk, G. D.; Broholm, C.; Ni, N.; Nandi, S.; Yethiraj, M.; Zaretsky, J.L.; Pulikkotil, J. J.; Kreyssig, A.; Lumsden, M.D.; Harmon, B. N.; Canfield, P.C. (American Physical Society, 2008-11-28)
      Inelastic neutron scattering measurements of the magnetic excitations in CaFe2As2 indicate that the spin wave velocity in the Fe layers is exceptionally large and similar in magnitude to the cuprates. However, the spin ...

    • Asymmetric domain nucleation and unusual magnetization reversal in ultrathin Co films with perpendicular anisotropy 

      Iunin, Y. L.; Kabanov, Y. P.; Nikitenko, V.I.; Cheng, X.M.; Clarke, D.; Tretiakov, O. A.; Tchernyshyov, O.; Shapiro, A. J.; Shull, R. D.; Chien, C.L. (American Physical Society, 2007-03-16)
      We report unexpected phenomena during magnetization reversal in ultrathin Co films and Co/Pt multilayers with perpendicular anisotropy. Using magneto-optical Kerr microscopy and magnetic force microscopy we have observed ...

    • Biological applications of multifunctional magnetic nanowires 

      Reich, D.H.; Tanase, M.; Hultgren, A.; Bauer, L. A.; Chen, C. S.; Meyer, G. J. (American Institute of Physics, 2003-05-15)
      Magnetic particles that can be bound to cells and biomolecules have become an important tool for the application of force in biology and biotechnology. Multifunctional magnetic nanowires fabricated by electrochemical ...

    • Bound spinons in an antiferromagnetic S=1/2 chain with a staggered field 

      Kenzelmann, M.; Chen, Y.; Broholm, C.; Reich, D.H.; Qiu, Y. (American Physical Society, 2004-07-02)
      Inelastic neutron scattering was used to measure the magnetic field dependence of spin excitations in the antiferromagnetic S=1/2 chain CuCl2·2(dimethylsulfoxide) in the presence of uniform and staggered fields. Dispersive ...

    • Broken parity and a chiral ground state in the frustrated magnet CdCr2O4 

      Chern, Gia-Wei; Fennie, C. J.; Tchernyshyov, Oleg (American Physical Society, 2006-08-01)
      We present a model describing the lattice distortion and incommensurate magnetic order in the spinel CdCr2O4, a good realization of the Heisenberg 'pyrochlore' antiferromagnet. The magnetic frustration is relieved through ...

    • 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, Christopher A.; Markovic, Nina (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, Gai-Wei; 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, ...