Numerical analysis of surface and leaky surface acoustic waves in new piezoelectric KNBO3, PKN, and LGN crystals

We perform a numerical analysis of the properties of surface acoustic waves (SAW) as well as leaky surface acoustic waves (LSAW) in piezoelectric KNbO^sub 3^, Pb^sub 2^KNb^sub 5^O^sub 15^ (PKN) and La^sub 3^Ga^sub 5.5^Nb^sub 0.5^O^sub 14^ (LGN) crystals. We determine optimal thermostable cuts and directions in which the SAWs have high phase velocity, a very high coefficient of electromechanical coupling. and a small angle between the phase and group velocities. We also found the cuts and directions in which the LSAWs can exist. The characteristics of the LSAWs (velocity, the coefficient of electromechanical coupling, angle between the phase and group velocities, temperature coefficient of velocity, and coefficient of surface absorption along the LSAW propagation direction) are calculated.[PUBLICATION ABSTRACT]