  We study surface acoustic waves (SAWs) in yttrium iron garnet (YIG)/zinc
oxide (ZnO) heterostructures, comparing the results of a computationally
lightweight analytical model with time-resolved micro-focused Brillouin light
scattering data. Interdigital transducers (IDTs), with operational frequencies
in the gigahertz regime, were fabricated on 50 and 100nm thin films of YIG
prior to sputter deposition of 830nm and 890nm films of piezoelectric ZnO. We
find good agreement between our analytical model and micro-focused Brillouin
light scattering data of the IDT frequency response and SAW group velocity,
with clear differentiation between the Rayleigh and Sezawa-like modes. This
work paves the way for the study of SAW-spin wave (SW) interactions in low SW
damping YIG, with the possibility of a method for future energy-efficient SW
excitation.
