High Velocity Acoustical Head Wave on Surface of ST Quartz

According to surface transient excitation theory of elastic wave for piezoelectric crystal, in the surface of a piezoelectric crystal can exist acoustical high velocity head wave except the general surface acoustic wave (SAW). Such a mode is to propagate with the group velocity of the longitudinal bulk wave along the crystal surface. For ST quartz its value is 5.744xl0³m/s, which agrees with our experiments. The fact that the longitudinal head wave mode has a high propagation velocity offers potential applications for high frequency SAW devices.