A GHz operating ScAlN based SAW resonator used for Surface Acoustic Waves/Spin Waves Coupling
preprintposted on 08.04.2022, 03:57 by Ioana ZdruIoana Zdru, Claudia Nastase, Lars Hess, Florin Ciubotaru, Alexandra Nicoloiu, Dan Vasilache, Matthijn Dekkers, Moritz Geilen, Cristina Ciornei, Adrian Dinescu, Christoph AdelmannChristoph Adelmann, Mathias Weiler, Philipp Pirro, Alexandru Muller
A thin ScAlN layer was deposited on high resistivity (111) oriented silicon and two port surface acoustic wave (SAW) devices were manufactured, using advanced nanolithographic techniques, on this material. The Surface Acoustic Wave and Spin Wave (SAW/SW) coupling was performed via a thin ferromagnetic layer (Ni) placed between the interdigitated transducers (IDTs) of the SAW device. Since the phase velocity in this material is lower than in the Si substrate, both Rayleigh (4.67 GHz) and Sezawa (8.05 GHz) propagation modes could be observed. The amplitude of the S21 parameter around the two resonances was measured for values of the magnetic field µ0H from -280 to +280 mT, at different angles (θ) between the SAW propagation direction and the magnetic field direction. A maximum decrease of 2.54 dB occurred in S21 for the Rayleigh mode at µ0H = -90 mT, and of 7.24 dB for the Sezawa mode at µ0H =-203 mT, both at θ = 45°. These values were extracted from time gated processing of the frequency domain raw data.