Measurement of spin diffusion length in sputtered Ni films using a special exchange-biased spin valve geometry

The authors report the spin diffusion length at 4.2 K in sputtered Ni of l(sf)(Ni)=21 +/- 2 nm, and spin-dependent scattering parameters in Ni and at Ni/Cu interfaces. They have employed current perpendicular to plane giant magnetoresistance in both a traditional and an alternative exchange-biased spin valve geometry that inserts a Ni spoiler layer into a Py/Cu/Py spin valve. Fits to data of A Delta R vs Ni thickness using Valet-Fert theory [Phys. Rev. B 48, 7099 (1993)] show good agreement between fit parameters for both sample geometries.