Intrinsic and extrinsic contributions to spin scattering in Pt

We utilize nanoscale spin valves with Pt spacer layers to characterize spin scattering in Pt. Analysis of the spin lifetime determined from our measurements indicates that the extrinsic Elliot-Yafet spin scattering is dominant at room temperature, while the intrinsic Dyakonov-Perel mechanism dominates at cryogenic temperatures. The significance of the latter is supported by the suppression of spin relaxation in Pt layers interfaced with a ferromagnet, likely caused by the competition between the effective exchange and spin-orbit fields.