Investigation of 90° coupling in Fe/Ag/Fe structures: "Loose spins'' and fluctuation mechanism
Schäfer, M. ; Demokritov, S. ; Müller-Pfeiffer, S. ; Schäfer, R. ; Schneider, M. ; Grünberg, P. ; Zinn, W.
[S.l.] : American Institute of Physics (AIP)
Published 1995
[S.l.] : American Institute of Physics (AIP)
Published 1995
| ISSN: |
1089-7550
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| Source: |
AIP Digital Archive
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| Topics: |
Physics
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| Notes: |
Results are outlined of experimental work concerning Slonczewski's theories explaining 90° coupling: "loose spin'' theory and thickness-fluctuation mechanism. The loose spin theory suggests that 90° coupling originates from paramagnetic impurities in the interlayer of an exchange-coupled layered structure. The influence of these paramagnetic impurities on the magnetic exchange coupling was studied using the wedge technique. High-quality single-crystalline Fe/Ag/Fe samples were prepared in UHV and each sample consisted of two wedges: one wedge with additional Fe deliberately inserted during growth into the Ag interlayer and one wedge with a pure Fe/Ag/Fe structure. The detailed analysis of magneto-optic hysteresis loops revealed quantitatively the bilinearly and the 90° coupling strength. As predicted by loose spin theory additional Fe in the Ag spacer lead to a strong temperature dependence of the 90° coupling. According to the theory an increase of 90° coupling strength proportional to impurity concentration was detected while the strength of bilinear coupling decreased. For the pure Fe/Ag/Fe structure, a linear increase of the 90° coupling strength with decreasing temperature was observed. This result can be explained within the fluctuation mechanism which creates 90° coupling through a combination of interface roughness and intralayer ferromagnetic exchange. © 1995 American Institute of Physics.
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| Type of Medium: |
Electronic Resource
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| URL: |