Enhancement of spin-orbit torques by change in uniaxial in-plane magnetic anisotropy of Py/Pt bilayers on single crystal 128 degrees Y-Cut LiNbO3 substrate

We have investigated the correlations between the in-plane uniaxial magnetic anisotropy (K-u) and spin-orbit torque (SOT) of Ni80Fe20 (Py)/Pt thin films sputtered on a single-crystal 128 & DEG; Y-Cut LiNbO3 (LNO) substrate by performing second-harmonic voltage measurements. The results show that the value of the damping-like (DL) SOT torque varies with the angle chi between K-u and the applied current and increases with chi from 0 & DEG; to 90 & DEG;. The effective spin Hall angle theta SH , Pt eff = 0.073 and 0.123 for chi = 0 and 90 & DEG;, respectively, indicate a difference of approximately 1.7 times. The theta SH , Pt eff at chi = 90 & DEG; is greater because the direction of the DL-SOT on the magnetization is the same as the K-u direction. This result implies that the effective spin Hall angle can be controlled by the K-u direction of the ferromagnetic metal layer induced on the LNO substrate, thereby providing valuable insight for the development of spin devices using SOT.