Dependence of the inverse spin Hall and spin rectification voltage on the aspect ratio of thin films.

• Distribution of induced microwave current in Py film depends on its geometry. • SRE signal can be neglected at specific magnetic field angle and geometry for Py film. • Pure ISHE signal can be obtained directly in Py(20 nm)/Ta(10 nm) bilayer (40 μm × 8 mm). • Spin Hall angle value of Ta in Py/Ta bilayer is similar to that of some literatures. We present a method to directly obtain the pure inverse spin Hall effect (ISHE) signal without the spin rectification effect (SRE) signal in ferromagnetic metal(FM)/nonmagnetic metal(NM) bilayers. This method is based on a fact that the distribution of the induced microwave current is largely dependent on the geometries of the samples. The ISHE signal can be maximized through shaping the samples and tuning the magnetic field directions, while the SRE signal can be minimized below the detection limit. This provides also a fast and simplified method to measure the ISHE signal in a wide frequency range. The spin Hall angle of Ta in a Py/Ta bilayer is −0.027 ± 0.015 in a wide frequency range. [ABSTRACT FROM AUTHOR]