Title: Experimental study of extrinsic spin Hall effect in CuPt alloy,
Abstract: We have experimentally studied the effects on the spin Hall angle due to
systematic addition of Pt into the light metal Cu. We perform spin torque
ferromagnetic resonance measurements on Py/CuPt bilayer and find that as the Pt
concentration increases, the spin Hall angle of CuPt alloy increases. Moreover,
only 28% Pt in CuPt alloy can give rise to a spin Hall angle close to that of
Pt. We further extract the spin Hall resistivity of CuPt alloy for different Pt
concentrations and find that the contribution of skew scattering is larger for
lower Pt concentrations, while the side-jump contribution is larger for higher
Pt concentrations. From technological perspective, since the CuPt alloy can
sustain high processing temperatures and Cu is the most common metallization
element in the Si platform, it would be easier to integrate the CuPt alloy
based spintronic devices into existing Si fabrication technology.