MAGNETIC JUNCTIONS USING ASYMMETRIC FREE LAYERS AND SUITABLE FOR USE IN SPIN TRANSFER TORQUE MEMORIES

摘要

A magnetic junction usable in a magnetic device is described. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, an asymmetric free layer and a perpendicular magnetic anisotropy (PMA) inducing layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer is between the nonmagnetic spacer layer and the PMA inducing layer. The asymmetric free layer includes a first ferromagnetic layer having a first boron content and a second ferromagnetic layer having a second boron content. The second boron content is less than the first boron content. The first boron content and the second boron content are each greater than zero atomic percent. The first and second ferromagnetic layers each contain at least one of Co and CoFe. The magnetic junction is configured such that the asymmetric free layer is switchable between stable magnetic states when a write current is passed through the magnetic junction.

主权项

1. A magnetic junction for use in a magnetic device comprising:
a pinned layer; a nonmagnetic spacer layer; an asymmetric free layer, the nonmagnetic spacer layer residing between the pinned layer and the asymmetric free layer, the asymmetric free layer including a first ferromagnetic layer having a first boron content and a second ferromagnetic layer having a second boron content, the second boron content being less than the first boron content, the first boron content and the second boron content being greater than zero atomic percent, first ferromagnetic layer and the second ferromagnetic layer each containing at least one of Co and CoFe; and a perpendicular magnetic anisotropy (PMA) inducing layer, the free layer being between the PMA inducing layer and the asymmetric free layer; wherein the magnetic junction is configured such that the asymmetric free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.