Polarized neutron reflectivity studies of biquadratic coupling in [Fe/Cr] (100) and [Fe/Al] (100) superlattices and films (invited) (abstract) : The 6th joint magnetism and magnetic materials (MMM)-intermag conference
Ankner, J. F. ; Schreyer, A. ; Zabel, H. ; Borchers, J. A. ; Majkrzak, C. F. ; Schäfer, M. ; Wolf, J. A. ; Grünberg, P. ; Filipkowski, M. E. ; Gutierrez, C. J. ; Krebs, J. J. ; Prinz, G. A.
[S.l.] : American Institute of Physics (AIP)
Published 1994
[S.l.] : American Institute of Physics (AIP)
Published 1994
| ISSN: |
1089-7550
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| Source: |
AIP Digital Archive
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| Topics: |
Physics
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| Notes: |
Sensitivity to magnetic atoms and low intrinsic absorption characterize the interaction of neutrons with matter. Consequently, polarized neutron reflectivity provides a unique means of performing depth-resolved vector magnetometry. We have used this technique to determine the magnetization depth profiles of Fe/Cr superlattices. Superlattices of bilayer composition [55 A(ring) Fe/17 A(ring) Cr], grown at 523 K, exhibit biquadratic coupling with large saturation fields (∼3 kOe), while those grown at 293 K are ferromagnetically ordered. We have directly measured the evolution of the coupling angle between adjacent Fe layers as a function of applied field and will discuss how bilinear, biquadratic, and external field terms produce the observed order. The weaker coupling found in the Fe/Al system makes possible the investigation of a range of spin configurations at temperatures that do not endanger the sample. We have mapped the phase diagram of a [42 A(ring) Fe/12 A(ring) Al/39 A(ring) Fe] (100) trilayer and find evidence of biquadratic coupling at low temperatures and fields (e.g., when H=180 Oe, the Fe layer spins relax away from ferromagnetic alignment below T≈170 K). Our measurements agree qualitatively with energy minimization calculations and the results of bulk magnetometry.
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| Type of Medium: |
Electronic Resource
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| URL: |