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Spatial fluctuations of loose spin coupling in CuMn/Co multilayers.
1School of Physics, University of Western Australia, Crawley, WA6009, Australia. Thomas.Saerbeck@ansto.gov.au
Physical Review Letters
|October 27, 2011
Summary
Magnetic impurities in copper/cobalt multilayers enhance interlayer coupling. Positional disorder of manganese ions creates a new biquadratic coupling contribution, affecting magnetic domain behavior.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Magnetism
Background:
- Interlayer exchange coupling (IEC) is crucial for spintronic devices.
- Understanding IEC in magnetic multilayers with impurities is essential for device performance.
- Manganese (Mn) impurities can significantly alter magnetic properties.
Purpose of the Study:
- To investigate magnetic impurity-mediated interlayer exchange coupling in Cu/Co multilayers.
- To elucidate the role of manganese impurity distribution on biquadratic coupling.
- To explore the impact of positional disorder on magnetic domain behavior.
Main Methods:
- Polarized neutron reflectometry (PNR) for depth-resolved magnetic structure.
- Magnetic X-ray techniques for element-specific magnetic information.
- Loose spin model adapted for three-dimensional impurity distribution.
Main Results:
- Observed temperature and magnetic field dependent biquadratic coupling.
- Positional disorder of Mn impurities enhances biquadratic coupling via J(2)(fluct).
- Demonstrated temperature-dependent canting of magnetic domains due to impurity distribution.
Conclusions:
- Positional disorder of magnetic impurities is a key factor in enhancing biquadratic coupling.
- The findings provide insights into impurity effects on Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling.
- Results highlight the importance of impurity distribution for controlling magnetic properties in multilayers.
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