Now showing items 1-15 of 15

    • 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 ...
    • 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 ...
    • 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 ...
    • 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 ...
    • 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, ...
    • 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 ...
    • Long-range exchange coupling between a ferromagnet and an antiferromagnet across a nonmagnetic spacer layer 

      Gokemeijer, N.J.; Ambrose, T.; Chien, C.-L.; Wang, N.; Fung, K.K. (American Institute of Physics, 1997-04-15)
      The antiferromagnet/ferromagnet exchange coupling giving rise to a shifted hysteresis loop has usually been considered an interfacial effect. We show evidence that this exchange coupling between an antiferromagnet (CoO) ...
    • Longitudinal and perpendicular exchange bias in FeMn/(FeNi/FeMn)n multilayers 

      Sun, L.; Zhou, S.M.; Searson, P.C.; Chien, C.-L. (American Institute of Physics, 2003-05-15)
      Exchange bias in ferromagnetic (FM)/antiferromagnetic (AF) bilayers is usually investigated in the longitudinal configuration with the exchange coupling established in the film plane. In this work, we report on the ...
    • Magnetic core loss of ultrahigh strength FeCo alloys 

      Cheng, X.M.; Zhang, X.K.; Zhang, D.Z.; Lee, S.H.; Duckham, A.; Weihs, T. P.; Cammarata, R.C.; Chien, C.-L. (American Institute of Physics, 2003-05-15)
      Hiperco® 50 alloy heat treated between 450 and 650°C exhibits superior mechanical properties. We report the measurements of the ac core loss at various frequencies up to 4500 Hz of the Hiperco® 50 alloy samples annealed ...
    • Magnetic properties of one-dimensional quasiperiodic Co/Pt multilayers 

      Zhu, L.Y.; Cheng, X.M.; Chien, C.-L. (American Institute of Physics, 2006-04-15)
      We have fabricated Fibonacci [Co/Pt] multilayers with two constituent Co/Pt bilayers, as well as periodic multilayers of the same Co/Pt bilayers, all of which exhibit perpendicular magnetic anisotropy. Magnetic properties ...
    • Stripes in thin ferromagnetic films with out-of-plane anisotropy 

      Clarke, David; Tretiakov, O. A.; Tchernyshyov, O. (American Physical Society, 2007-05-01)
      We examine the T=0 phase diagram of a thin ferromagnetic film with a strong out-of-plane anisotropy (e.g., Co/Pt multilayers) in the vicinity of the reorientation phase transition. The phase diagram in the anisotropy-applied-field ...
    • Studies of deposition order anomaly of exchange coupling in bilayers and trilayers of NiFe and CoO 

      Ambrose, T.; Leifer, K.; Hemker, K. J.; Chien, C. L. (American Institute of Physics, 1997-04-15)
      The temperature dependence of the exchange field and coercivity and the effect of deposition order have been studied in a series of bilayer (NiFe/CoO and CoO/NiFe) and trilayer (NiFe/CoO/NiFe) films. A profound difference ...