Spin Hall Angle and Spin Diffusion Length in SrIrO3 via Hanle magnetoresistance

The Spin Hall Angle, θ_SH and the spin diffusion length, λ are two parameters that describe a spin-orbit coupled material’s efficiency in transducing between charge and spin currents. The Hanle Magnetoresistance (1) is the result of spin precession and diffusion in the presence of an external magnetic field and spin Hall effect. The Hanle magnetoresistance provides a way of assessing θ_SH and λ without the need for neighboring magnetic materials or control over interfacial exchange. We apply this technique to thin films (15nm) of SrIrO3 on SrTiO3 substrates. SrIrO3 is a strong candidate for potential spintronics devices, owing to its large θ_SH of 0.1-0.4 in 5-15nm films (2). These measurements required the construction of a Kelvin resistance bridge to resolve magnetoresistance responses of 1 part in 10⁶. We present initial measurements and discuss these results in the context of HMR physics and other magnetoresistive effects.