In stacks using a Ru/Ta composite spacer [Pt/Co]6/Ru/Ta/CoFeB/MgO, both strong interlayer exchange coupling and perpendicular magnetic anisotropy are achieved. The composite spacer has the additional advantages of high post-annealing stability over a conventional Ru spacer; for a Ru (0.8 nm)/Ta (0.4 nm) spacer, where the antiparallel coupling is strongest, the coupling strength remains nearly constant at the highest annealing temperature of 375 °C. An interlayer exchange coupling is observed at very small Ru thicknesses down to 0.2 nm, which can be compared with the previous limit of 0.6 nm.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)