Abstract
Switching characteristics and magnetoresistance of spin valves with perpendicular anisotropy based on Co-Fe/Pd multilayers deposited by ultrahigh vacuum (UHV) sputtering have been studied. In unpatterned thin films without exchange bias, high current-in-plane giant magnetoresistance (CIP-GMR) of 9.7% and 15.2% in single-spin valves (SSVs) and dual-spin valves (DSVs) was measured, a significant improvement over previous work. We describe the effects of a Ta seed layer and postdeposition annealing on the perpendicular anisotropy and magnetoresistance of Co-Fe/Pd spin valves, which can be attributed to improvements in the fcc (111) orientation of Pd and the formation of Co-Pd alloys at the Co-Fe/Pd interfaces, respectively. We also show that the coercivity of the layers can be tuned by varying the Co-Fe alloy composition in the multilayers, and describe the minor loops of perpendicular DSVs that exhibit four distinct resistance states, which is a potential structure for multistate storage devices.
Original language | English |
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Pages (from-to) | 2612-2615 |
Number of pages | 4 |
Journal | IEEE Transactions on Magnetics |
Volume | 44 |
Issue number | 11 PART 2 |
DOIs | |
Publication status | Published - Nov 2008 |
Externally published | Yes |
Keywords
- Dual-spin valves (DSVs)
- Giant magnetoresistance (GMR)
- Multistate storage
- Perpendicular magnetic anisotropy (PMA)
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering