High coupling and high velocity surface acoustic waves using achyphen;axis oriented ZnO film on translucent Al2O3ceramics

摘要

The layered structure comprising achyphen;axis normally oriented ZnO piezoelectric film and a translucent Al2O3ceramic substrate which has a high surfacehyphen;acoustichyphen;wave velocity and a small surface roughness has given both a high phase velocityVpand a high couplingk2for the 0th (Rayleigh) mode, 1st (Sezawa) mode, and leaky mode surface acoustic waves. The measured maximum values ofk2are 3.6percnt; for the 0th mode ath/lgr;=0.45 whereVpis 3.2 km/s, 5.7percnt; for the 1st mode ath/lgr;=0.21 whereVpis 5.6 km/s, and 6.7percnt; for the leaky mode ath/lgr;=0.16 whereVpis 6.2 km/s, where the interdigital transducers are located at the interface in measuring the above values, and also electrically floating plane metals are on top of the ZnO film for the last two values.