Acoustically-driven ferromagnetic resonance in ferrimagnetic insulator Y₃Fe₅O₁₂ with magnetic anisotropy

Spin wave devices seek to efficiently transport spin information by launching propagating waves of spin excitations in a lattice.^1-4 Previous studies have achieved spin wave launching by triggering ferromagnetic resonance with surface acoustic waves (SAWs) using the magnetoelastic effect, a phenomenon known as acoustically-driven ferromagnetic resonance (ADFMR). While these ADFMR studies have primarily focused on ferromagnetic metals which have short coherence lengths, ADFMR in a ferromagnetic insulator has the potential to create spin waves with a longer coherence length.^5,6 In this study, we detect spin wave launching due to ADFMR in the ferrimagnetic insulator Y₃Fe₅O₁₂; (yttrium iron garnet, YIG). Interdigitated transducers were used to send and receive bursts of SAWs on piezoelectric Y-cut LiNbO₃ substrates patterned with YIG thin films under an applied field. The transmitted SAW signals were partially absorbed by the YIG films at the resonant field. Angle-dependence of this absorption indicates ADFMR and therefore spin wave launching. We also discuss the effect of in-plane magnetic anisotropy on the ADFMR signature. These results expand the potential for spin wave devices to create low loss spintronics.