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

摘要

Provided is a magnetic junction for a spin torque memory using asymmetric free layers. The magnetic junction includes a fixing layer, a nonmagnetic spacer layer, an asymmetric free layer and a perpendicular magnetic anisotropy (PMA) induction layer. The nonmagnetic spacer layer is between the PMA induction layer and the asymmetric free layer. The asymmetric free layer includes a ferromagnetic layer having a first boron content and a second ferromagnetic layer having a second boron content. The second content is less than the first boron content. The first and the second boron content are greater than zero atomic percent. The free layer exists between the PMA induction layer and the nonmagnetic space layer. The magnetic junction allows the asymmetric free layer to be switchable between stable magnetic states, when a write current is passed through the magnetic junction.