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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 ...

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 ...

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 ...

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 ...

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 ...

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) ...

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. ...

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 ...

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 ...