Session Z32: Focus Session: Magnetoresistance and Spin-dependent Transport

11:15 AM–1:51 PM, Friday, March 20, 2009
Room: 336

Sponsoring Units: GMAG DMP FIAP
Chair: Kiran Thadani, Cornell University

Abstract ID: BAPS.2009.MAR.Z32.12

Abstract: Z32.00012 : Enhancement of Biquadratic Coupling in Co/Fe/MgO/Fe(001)

1:27 PM–1:39 PM

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Authors:

  Jared Wong
    (University of California, Riverside)

  Yueh-Feng Chiang
    (University of California, Riverside)

  Andrew Hoff
    (University of California, Riverside)

  Xiaojing Tan
    (University of California, Riverside)

  Yan Li
    (University of California, Riverside)

  Keyu Pi
    (University of California, Riverside)

  Wei Hau Wang
    (University of California, Riverside)

  Harry Tom
    (University of California, Riverside)

  Roland Kawakami
    (University of California, Riverside)

One interesting aspect of the interlayer exchange coupling (IEC) across MgO is that in addition to the bilinear coupling, a biquadratic coupling favoring 90\r{ } magnetization alignment has been observed [1, 2, 3]. We investigate IEC in Co/Fe/MgO/Fe(001) and the affects of non-ideal aspects of the MgO-heterostructure, such as interface oxidation and impurities in the MgO, via molecular beam epitaxy (MBE) synthesis and magneto-optic Kerr effect (MOKE) measurements across wedged samples. By independently varying the oxygen content of the MgO film and the Fe/MgO interface, we find that the biquadratic coupling is correlated to the interfacial oxidation. Furthermore, the temperature dependence of the biquadratic coupling exhibits a strong increase at low temperatures. Our findings strongly support the loose spin mechanism as the origin of the biquadratic coupling across MgO[4]. 1. J. Faure-Vincent, C. Tiusan, C. Bellouard, et al., Phys. Rev. Lett. 89, 107206 (2002). 2. T. Katayama, S. Yuasa, J. Velev, et al., Appl. Phys. Lett. 89, 112503 (2006). 3. E. Snoeck, P. Baules, G. BenAssayag, et al., J. Phys.: Cond. Mat. 20, 055219 (2008). 4. J. C. Slonczewski, J. Appl. Phys. 73, 5957 (1993).

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.Z32.12