Dense plasma irradiated platinum with improved spin Hall effect

TL;DR

This paper demonstrates that dense plasma irradiation of platinum introduces defects that significantly enhance its spin Hall effect, offering a new approach for improving spintronic device performance.

Contribution

The study presents a novel plasma irradiation technique to increase the spin Hall angle in platinum by inducing lattice disorder, without disrupting spin-orbit torque symmetry.

Findings

2.4 times increase in spin Hall effect after plasma treatment

Enhanced spin-orbit coupling due to introduced lattice defects

Potential for improved spintronic device efficiency

Abstract

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.