  The impurity incorporation in host high-spin orbit coupling materials like
platinum has shown improved charge-to-spin conversion by modifying the up-spin
and down-spin electron trajectories by bending or skewing them in opposite
directions. This enables efficient generation, manipulation, and transport of
spin currents. In this study, we irradiate the platinum with non-focus dense
plasma to incorporate the oxygen ion species. We systematically analyze the
spin Hall angle of the oxygen plasma irradiated Pt films using spin torque
ferromagnetic resonance. Our results demonstrate a 2.4 times enhancement in the
spin Hall effect after plasma treatment of Pt as compared to pristine Pt. This
improvement is attributed to the introduction of disorder and defects in the Pt
lattice, which enhances the spin-orbit coupling and leads to more efficient
charge-to-spin conversion without breaking the spin-orbit torque symmetries.
Our findings offer a new method of dense plasma-based modification of material
for the development of advanced spintronic devices based on Pt and other heavy
metals.
