Ferromagnetic - ferrimagnetic transition in a trilayer Co/Ru/Co synthetic ferrimagnet film
Abstract
Co/Ru/Co synthetic ferrimagnets and antiferromagnets have found application in spin valves and recently in magnetic recording media to pin the moments of the ferromagnetic layer. While the antiferromagnetically coupled Co layers are known to reverse simultaneously during magnetization reversal, less is known about the transition between the ferromagnetic state and the ferrimagnetic state. Using polarized neutron reflectometry (PNR), we have studied both ferromagnetic to ferrimagnetic and ferrimagnetic to ferromagnetic transitions in antiferromagnetically coupled trilayer of Co(44A)/Ru(6A)/Co(130A) with uniaxial anisotropy. With the field applied along the easy axis of magnetization during the transitions, the Co moments rotate from the easy axis, leading to an enhancement of the neutron spin-flip reflectivities. The enhancements were symmetric along both directions of the transition. PNR measurements also reveal a small amount of rotated moment in the ferrimagnetic state, while simultaneous reversal of both Co layers as the net magnetization reverses was confirmed by a comparison of the magnetic depth profiles. This work was supported by grants NSF DMR 02-13985 and DOE/EPSCoR DE-FG02-02ER45966, and by ORNL, managed for the U.S. DOE by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725. Work at Argonne supported by the U.S. DOE, BES-Materials Sciences, under Contract #W-31-109-ENG-38.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2003
- Bibcode:
- 2003APS..MARK28006L