  Coupling between dynamic strain and magnetization in ferromagnetic thin films
has attracted special consideration as it presents both intriguing fundamental
physics problems and technological importance for potential multi-functional
devices and information handling. The dynamic strain can be generated by
acoustic waves including bulk, surface or guided waves. In this work, we
propose the theoretical and experimental investigation of the interaction of
pure shear horizontal (SH) wave with a uniaxial multilayered TbCo2/FeCo thin
film in a delay line configuration fabricated on Quartz ST-90X cut. We evaluate
theoretically the evolution of phase velocity as a function of magnetic field
and experimentally the variation of the transmission coefficient. A
piezomagnetic model was developed allowing us to calculate the elastic
stiffness constants of the multilayer as a function of the applied magnetic
field. The model was also implemented for acoustic waves dispersion curves
calculation. We show that the evolution of phase velocity is dominated by the
C66 elastic stiffness constant variation as expected for the case of shear
horizontal surface wave. The fabricated device let us exciting both fundamental
and third harmonic shear mode at 410 MHz and 1.2 GHz, respectively. For both
modes, the theoretical results corroborate very well the experimental ones. At
1.2 GHz the mode exhibits a maximum phase velocity shift close to 2.5% and an
attenuation reaching 500 dB/cm, for a sensitivity as high as 250 ppm/Oe. The
reported theoretical model and experimental results are of tremendous interest
for the development of advanced devices for magnetic field sensing applications
as well as investigating magnon-phonon interaction at a fundamental level.
