First-principles calculation of the nonadiabatic spin transfer torque in Ni and Fe.
Keith Gilmore, Ion Garate, Allan H. MacDonald, and M. D. Stiles
Phys. Rev. B 84, 224412 (2011)

Spin-transfer torque parameter versus resistivity for several ratios (r = 0.5, 1.0, 2.0) of spin-dependent scattering rates for Ni. The top panel gives β, the middle panel β/α, and the bottom panel βσP/(ασ). The dashed vertical lines indicate
the approximate room-temperature resistivity.