The remanent states and magnetization reversal mechanisms for nanopatterned Co/Cu/Py (Py=Permalloy) spin-valve elements with slotted-ring shapes have been studied using off-axis electron holography. The hysteresis loops of individual elements were quantitatively determined for slots parallel to the applied field, indicating that three identifiably separate steps occurred during reversal. Magnetization configurations at each stage were directly visualized, suggesting that Co and Py layers undergo coherent switching from onion state to flux-closure state and finally to reverse onion state. The effective loop rotation direction for the Py layer was clockwise.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)