  Effective spin mixing conductance (ESMC) across the nonmagnetic metal
(NM)/ferromagnet interface, spin Hall conductivity (SHC) and spin diffusion
length (SDL) in the NM layer govern the functionality and performance of pure
spin current devices with spin pumping technique. We show that all three
parameters can be tuned significantly by the spin orbit coupling (SOC) strength
of the NM layer in systems consisting of ferromagnetic insulating Y3Fe5O12
layer and metallic Pd1-xPtx layer. Surprisingly, the ESMC is observed to
increase significantly with x changing from 0 to 1.0. The SHC in PdPt alloys,
dominated by the intrinsic term, is enhanced notably with increasing x.
Meanwhile, the SDL is found to decrease when Pd atoms are replaced by heavier
Pt atoms, validating the SOC induced spin flip scattering model in polyvalent
PdPt alloys. The capabilities of both spin current generation and spin charge
conversion are largely heightened via the SOC. These findings highlight the
multifold tuning effects of the SOC in developing the new generation of
spintronic devices.
