This paper reports the direct electrical measurement of the spin Hall effect (SHE) in a diffusive metallic conductor, aluminum (Al). The SHE is the generation of a spin current perpendicular to an applied electric field, resulting in a spin imbalance. The authors use a ferromagnetic electrode with a tunnel barrier to inject spin-polarized electrons into an Al Hall cross, and measure the resulting voltage due to the spin Hall effect. The voltage is proportional to the component of the injected spins perpendicular to the plane defined by the spin current direction and the voltage probes. The experiments demonstrate that the SHE can be detected without the need for magnetic materials, offering potential for spintronic devices that integrate information processing and data storage. The SHE was first proposed by Dyakonov and Perel, and later by Hirsch. It can occur in paramagnetic materials due to spin-orbit interaction. The SHE can be extrinsic, arising from asymmetric scattering of spin-up and spin-down electrons, or intrinsic, resulting from band structure. The authors use a measurement scheme that isolates the SHE from other effects, such as anisotropic magnetoresistance and the standard Hall effect. The authors fabricate devices using electron beam lithography and a two-angle shadow-mask evaporation technique. The Al cross is first deposited on a Si/SiO2 substrate, then oxidized to form insulating Al2O3 barriers. The ferromagnetic electrodes are deposited at an angle, forming tunnel junctions with the Al strip. The spin polarization of the injected electrons depends on the effective tunnel conductances for spin-up and spin-down electrons. The authors measure the spin Hall resistance, RSH, as a function of the perpendicular magnetic field, B⊥. They find that RSH is proportional to sinθ, where θ is the angle between the magnetization of the FM electrodes and the electrode axis. The results show a linear response around B⊥=0, followed by saturation at B⊥sat. The spin Hall conductivity, σSH, is calculated from the measurements, and found to be in good agreement with theoretical predictions. The study demonstrates the direct measurement of spin-polarized currents without the need for ferromagnets, and shows that spin precession does not modify the spin Hall voltage for magnetic fields perpendicular to the substrate. The results provide new insights into spin-related phenomena and have implications for the development of spintronic devices.This paper reports the direct electrical measurement of the spin Hall effect (SHE) in a diffusive metallic conductor, aluminum (Al). The SHE is the generation of a spin current perpendicular to an applied electric field, resulting in a spin imbalance. The authors use a ferromagnetic electrode with a tunnel barrier to inject spin-polarized electrons into an Al Hall cross, and measure the resulting voltage due to the spin Hall effect. The voltage is proportional to the component of the injected spins perpendicular to the plane defined by the spin current direction and the voltage probes. The experiments demonstrate that the SHE can be detected without the need for magnetic materials, offering potential for spintronic devices that integrate information processing and data storage. The SHE was first proposed by Dyakonov and Perel, and later by Hirsch. It can occur in paramagnetic materials due to spin-orbit interaction. The SHE can be extrinsic, arising from asymmetric scattering of spin-up and spin-down electrons, or intrinsic, resulting from band structure. The authors use a measurement scheme that isolates the SHE from other effects, such as anisotropic magnetoresistance and the standard Hall effect. The authors fabricate devices using electron beam lithography and a two-angle shadow-mask evaporation technique. The Al cross is first deposited on a Si/SiO2 substrate, then oxidized to form insulating Al2O3 barriers. The ferromagnetic electrodes are deposited at an angle, forming tunnel junctions with the Al strip. The spin polarization of the injected electrons depends on the effective tunnel conductances for spin-up and spin-down electrons. The authors measure the spin Hall resistance, RSH, as a function of the perpendicular magnetic field, B⊥. They find that RSH is proportional to sinθ, where θ is the angle between the magnetization of the FM electrodes and the electrode axis. The results show a linear response around B⊥=0, followed by saturation at B⊥sat. The spin Hall conductivity, σSH, is calculated from the measurements, and found to be in good agreement with theoretical predictions. The study demonstrates the direct measurement of spin-polarized currents without the need for ferromagnets, and shows that spin precession does not modify the spin Hall voltage for magnetic fields perpendicular to the substrate. The results provide new insights into spin-related phenomena and have implications for the development of spintronic devices.