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The energy efficiency of the spin Hall effects (SHE) can be enhanced if the electrical conductivity is decreased without sacrificing the spin Hall conductivity. The resistivity of Pt films can be increased to 150–300 µΩ · cm by mesoscopic lateral confinement, thereby decreasing the conductivity. The SHE and inverse spin Hall effects (ISHE) in these mesoscopic Pt films are explored at 10 K by using the nonlocal spin injection/detection method. All relevant physical quantities are determined in situ on the same substrate, and a quantitative approach is developed to characterize all processes effectively. Extensive measurements with various Pt thickness values reveal an upper limit for the Pt spin diffusion length:   ⩽  0.8 nm. The average product of and the Pt spin Hall angle is substantial:   =  (0.142  ±  0.040) nm for 4 nm thick Pt, though a gradual decrease is observed at larger Pt thickness. The results suggest enhanced spin Hall effects in resistive mesoscopic Pt films. [ABSTRACT FROM AUTHOR]

Spin-flip probabilities from bulk defects and phonons are determined for the mesoscopic Cu channels of nonlocal spin valves (NLSVs). The NLSV spin signals are analyzed by a new approach to consistently extract the in situ values of the Cu spin diffusion length, effective spin injection (detection) polarization, and Cu resistivity. The size variations of the spin injectors (detectors) between NLSVs are treated by normalizing the spin signals to be commensurate with a standard injector (detector) size. The microstructure variations are statistically accounted for by measuring many NLSVs on the same substrate. From the Cu resistivity and spin diffusion lengths at 10 K and 295 K, the spin-flip probabilities from bulk defects and phonons are determined to be (3.9  ±  0.8)  ×  10−4 and (2.8  ±  1.2)  ×  10−4, respectively. [ABSTRACT FROM AUTHOR]