We present a theoretical description of spin-transfer torque in a spin valve with perpendicularly magnetized polarizer. The polarizer consisting of several ultrathin layers is considered as a single interfacial magnetic scatterer between two nonmagnetic layers, and is included in the theory based on diffusive transport via appropriate boundary conditions. The model has been used to study systematically the spin-transfer torque and current-induced switching in a spin valve with both perpendicular and in-plane polarizers and with in-plane magnetized free layer. The wave-function matching ab initio calculations have been used to determine transport parameters of the perpendicular polarizer. Additionally, the effect of disorder on the spin-transfer torque has been examined.

• Received 7 July 2013

DOI:https://doi.org/10.1103/PhysRevB.88.094422